What was one important discovery that the Curies made?
O A material's radioactivity cannot be changed by altering the material physically
O A material's radioactivity can be weakened or intensified by changing it chemically.
O Radioactive materials generally contain radium or polonium.
O Radioactive materials are found only in the form of salts.

Answers

Answer 1

Answer:

C is the answer to your question


Related Questions

Notice
10 January 2018
Gift A Tree
This is to inform students of Class XII to assemble in the ground on Saturday, 31 January
2018 at 8:00 in the morning to participate in a Tree Plantation Ceremony being organised
by the Environment Club as a part of the Farewell Programme.
Amita/Amit
Secretary, Environment Club)
Exercises
As the Head Boy/ Head Girl, Central Public School, draft a notice informing all students about
a wrist watch that was found near the school canteen.answar​

Answers

Answer:

gahwidsuacsgsuacayau1joagavahiq8wtw8quavakiafabajozyavqhaigavayquata

Explanation:

vahaiqgahiavavqugafayqigqvsbjsiagwyeiwvvs

why Ethyl amine is more basic than aniline​?

Answers

Answer:

Because a Lone pair of electrons on nitrogen is involved in delocalization.

Hope this helps you ( ◕ᴗ◕✿)

If it doesn't i'm sorry(◞ ‸ ◟)

Explanation:

In ethylamine ethyl is electron donating group. So more electrons are available aroudn nitrogen for donation. But in aniline phenyl group is electron attracting group.

Determine the relative formula mass of dihydrogen monoxide using the periodic table below.

A. 18 g/mol
B. 17 g/mol
C. 16 g/mol
D. 2 g/mol

Answers

The relative atomic mass of dihydrogen monoxide is 18g/mol

Dihydrogen monoxide is a molecule containing two atoms of hydrogen and one atom of oxygen i.e. H2O. It is widely regarded as WATER

To calculate the relative atomic mass of dihydrogen monoxide (H2O), we make use of the atomic mass of each element.

According to the periodic table:

Where; H = 1g/mol and O = 16g/mol

H2O = 1(2) + 16

= 2 + 16

= 18g/mol

Learn more at: https://brainly.com/question/17275626

The equilibrium constant K changes with changes in
the temperature.​

Answers

Answer:Equilibrium constants are changed if you change the temperature of the system. Kc or Kp are constant at constant temperature, but they vary as the temperature changes. You can see that as the temperature increases, the value of Kp falls.

What electron configuration represents Nitrogen? A. 2,2 B. 2,8,4 C. 2,4 D. 2,5

Answers

Answer:

D. 2:5

Explanation:

It has 5 valency electrons

[tex].[/tex]

In the given question, the electronic configuration of nitrogen is 2,5. The correct answer is option D.

The electronic configuration of an atom describes the arrangement of its electrons in different energy levels or orbitals.

Nitrogen has an atomic number of 7, which means it has 7 electrons.

The first energy level or shell can hold up to 2 electrons, and the second can hold up to 8 electrons. Nitrogen has 2 electrons in its first energy level and 5 electrons in its second energy level.

Therefore, the electronic configuration of nitrogen is 2,5, which means it has 2 electrons in its first energy level and 5 electrons in its second energy level. Option D is the correct answer.

Learn more about Electron Configuration here: https://brainly.com/question/14283892

#SPJ4

You find a clean 100-ml beaker, label it "#1", and place it on a tared electronic balance. You add small amount of unknown solid and place the
beaker with its contents on the balance. The recorded data is:
mass of the empty, clean beaker #1: 74.605 g
mass of the beaker #1 with the white solid: 74.896 g
Using the Law of Conservation of Mass, what is the mass of the unknown solid you placed in beaker #1?

Answers

Answer:

the mas is .291 g

Explanation:

the mass of a object does not change. so when added the substance the beaker. you had the mass of both objects together. you know the mass of the beaker and you know the mass of both. since mass does not change. the beakers mass is still 74.605g. the mass of both objects is 74.896. all you have to do is subtract the mass of the beaker from the total mass. 74.896 - 74.605 equals .291g. so the mass of the unknown substance Is .291g

Which molecule is butane?

Answers

Answer:

option c see image... and yw

The molecule shown in option C is butane.

What is butane?The organic compound with four carbon atoms and ten hydrogen atom lie in linear chain without any functional group is called butane.It is belongs to alkane family.

What is alkane?It is  acyclic saturated hydrocarbons organic compounds.It is also known as paraffin.An alkanes contain carbon atoms and hydrogen atoms bonded with single bond.It general formula is [tex]C_{n} H_{n+2}[/tex] .

To learn more about butane,

https://brainly.com/question/14818671

#SPJ2

Write down the molecular formula and molecular weight of carbon dioxide . ​

Answers

Answer:

CO2

Molar mass: 44.01 g/mol

Explanation:

CO2

A stock solution of magnesium chloride has a concentration of 120 mg mL. How many milliliters of the stock solution are required to prepare 1.5 L of 25 mg mL solution

Answers

312.5 mL of the stock solution are required to prepare 1.5 L of 25 mg mL solution.

In this problem you get that 312.5 mL of the stock solution are required to prepare 1.5 L of 25 mg mL solution.

First of all, you have to know that when it is desired to prepare a less concentrated solution from a more concentrated one, it is called dilution.

Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.

In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.

A dilution is mathematically expressed as:

Ci×Vi = Cf×Vf

where

Ci: initial concentrationVi: initial volumeCf: final concentrationVf: final volume

In this case, you know:

Ci= 120 [tex]\frac{mg}{mL}[/tex]Vi= ?Cf= 1.5 L= 1500 mL (beign 1 L= 1000 mL)Vf= 25 [tex]\frac{mg}{mL}[/tex]

Replacing in the definition of dilution:

120 [tex]\frac{mg}{mL}[/tex]× Vi= 25

Solving:

[tex]Vi=\frac{25\frac{mg}{mL}x1500 mL}{120 \frac{mg}{mL}}[/tex]

Vi= 312.5 mL

In summary, 312.5 mL of the stock solution are required to prepare 1.5 L of 25 mg mL solution.

Learn more about dilution:

https://brainly.com/question/20113402?referrer=searchResultshttps://brainly.com/question/22762236?referrer=searchResults

how do we use the circle of fifths

Answers

Explanation:

in the terms of interval,thats a major sixth up or a minor third using the circle of fifths simply move three position clock wise around the to find the relative minor! so starting from C,count one( G),two( D)and then three:A is related to minor key.

Choose the correct statement
a) The maximum value of principal quantum number (n) is 7
b) The angular quantum number (l) can receive value from 1 to (n-1)
c) The magnetic quantum number (ml) shows the energy of electron
d) The magnetic quantum number (ml) show how many orbitals in each subshell

Answers

Answer:

maybe number b is correct. ...thank you

Which element will have a higher electronegativity?
A. Fluorine
B. Hydrogen
C. Bromine
D. Phosphorus

Answers

Answer:

fluorine is the most electronegative element,

Explanation:

while francium is one of the least electronegative. (Helium, neon, and argon are not listed in the Pauling electronegativity scale, although in the Allred-Rochow scale, helium has the highest electronegativity.)

Answer:

A. Fluorine

Explanation:

It said that according to periodic law that the group seven elements are highly electronegativity and in reduce down the group

Which mean that it is Fluorine

Please help 15 points
What is the change in electrons for nitrogen in the
following reaction?
S + NO3 --> SO2 + NO

Answers

Nitrogen gained 4 electrons.

Because Nitrogen's redox number went from +6 to +2, it must have gained 4 electrons (-4) in order to achieve this number. Thus, Nitrogen is reduced.

Question 9 of 10
Which statement correctly describes magnetic field lines?
O A. They cross each other at right angles.
B. They always point away from a south pole.
C. They show the direction a south pole will point.
D. They join north pole to south pole..

Answers

In my opinion The answer is A

how many CH4 molecules are in 14.8 g of CH4

Answers

1.8021•1024 molecules

Answer:

[tex]\boxed {\boxed {\sf 5.56 \times 10^{23} \ molecules \ CH_4}}[/tex]

Explanation:

We are asked to find how many molecules of methane are in 14.8 grams of the substance.

1. Convert Grams to Moles

First, we convert grams to moles. We use the molar mass, or the mass of 1 mole of a substance. These values are equivalent to the atomic masses found on the Periodic Table, however the units are grams per mole instead of atomic mass units.

We are given the compound methane, or CH₄. Look up the molar mass of the individual elements (carbon and hydrogen).

C: 12.011 g/mol H: 1.008 g/mol

Check the formula for subscripts. Hydrogen (H) has a subscript of 4, so there are 4 moles of hydrogen in 1 mole of methane. We must multiply hydrogen's molar mass by 4, then add carbon's molar mass.

H₄: 1.008 * 4 = 4.032 g/mol CH₄: 12.011 + 4.032 = 16.043 g/mol

Now we use dimensional analysis to convert. To do this, we set up a ratio using the molar mass.

[tex]\frac {16.043 \ g \ CH_4 }{ 1 \ mol \ CH_4}[/tex]

Since we are converting 14.8 grams of methane to moles, we multiply by this value.

[tex]14.8 \ g \ CH_4 *\frac {16.043 \ g \ CH_4 }{ 1 \ mol \ CH_4}[/tex]

Flip the ratio so the units of grams of methane cancel.

[tex]14.8 \ g \ CH_4 *\frac{ 1 \ mol \ CH_4} {16.043 \ g \ CH_4 }[/tex]

[tex]14.8 *\frac{ 1 \ mol \ CH_4} {16.043}[/tex]

[tex]\frac {14.8}{16.043} \ mol \ CH_4= 0.9225207256 \ mol \ CH_4[/tex]

2. Moles to Molecules

Next, we convert moles to molecules. We use Avogadro's Number or 6.022  × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are moles of methane. Set up another ratio using Avogadro's Number.

[tex]\frac { 6.022 \times \ 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]

Multiply by the number of moles we calculated.

[tex]0.9225207256\ mol \ CH_4 * \frac { 6.022 \times \ 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]

The units of moles of methane cancel.

[tex]0.9225207256* \frac { 6.022 \times \ 10^{23} \ molecules \ CH_4}{ 1 }[/tex]

[tex]5.55541981 \times 10^{23} \ molecules \ CH_4[/tex]

3. Round

The original measurement of grams (14.8) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 5 in the thousandth place tells us to round the 5 in the hundredth place up to a 6.

[tex]5.56 \times 10^{23} \ molecules \ CH_4[/tex]

14.8 grams of methane is equal to approximately 5.56 × 10²³ molecules of methane.

8. Benzene is an aromatic hydrocarbon with molecular formula C6H6. a) Draw the ring structure of Benzene. [1] how will you prepare benzene from phenol​

Answers

When phenol is heated with zinc dust benzene is obtained.

Give 3 examples of chemical change and physical change in daily life

Answers

Explanation:

Physical change

★ Boiling of water

❤︎ freezing of water

❣︎ washing of clothes

♫︎ mixing black and brown stones

Chemical change

➪ making of dough

㋛︎ burning of wood

❥︎ cooking of the raw food

❁ burning of paper

ꨄ︎ rusting of iron

★★★➪➪➪➪ it was help to you

Briefly describe how you can use spectra as evidence of nuclear fusion in stars.

Answers

Spectra can be used as an evidence that nuclear fusion occurs in the star through the ability of the elements generated to absorb light at specific wavelength.

The internal part of the star is made up of hydrogen gas, with a little helium.

The helium atom is formed through the nuclear fusion reaction that occurs in the core of the star.

Nuclear fusion reaction involves the combination of two or more atoms which leads to the formation of a new atom with the emission of great energy. This reaction leads to formation of helium elements in the core of the stars.

To detect if nuclear fusion reaction is occurring in the stars, a spectrum is used.

Because each element emits or absorbs light only at specific wavelengths, the chemical composition of stars can be determined using a spectrum.

Learn more here:

https://brainly.com/question/18545784

An object with a mass of 3kg has a force of 9 newtons applied to it. What
is the resulting acceleration of the object?

Answers

Answer:

3 m/s^2

Explanation:

m = 3 kg

F = 9 N

Use Newton's Second Law: F = ma

9 = 3a

a = 3 m/s^2

a sample of oxygen occupied 568 ml. when the pressure increased to 911.6 mm Hg. at constant temperature, what volume did the gas initially occupy when the pressure was 248.71 mm Hg?
a 2082
b 155.0
c 2114
d 399.2

Answers

Answer:

[tex]\boxed {\boxed {\sf A. \ 2082 \ mL}}[/tex]

Explanation:

We are asked to find the initial volume of a gas given a change in pressure. Since the temperature remains constant, we are only concerned with volume and pressure. We will use Boyle's Law, which states the volume of a gas is inversely proportional to the pressure. The formula for this law is:

[tex]P_1V_1= P_2V_2[/tex]

The pressure was initially 248.71 millimeters of mercury, but the volume is unknown.

[tex]248.71 \ mm \ Hg * V_1 = P_2V_2[/tex]

The pressure is increased to 911.6 millimeters of mercury and the volume is 568 milliliters.

[tex]248.71 \ mm \ Hg * V_1 = 911.6 \ mm \ Hg * 568 \ mL[/tex]

We are solving for the initial volume, so we must isolate the variable V₁. It is being multiplied by 248.71 millimeters of mercury. The inverse operation of multiplication is division, so we divide both sides by 248.71 mm Hg.

[tex]\frac {248.71 \ mm \ Hg * V_1 } {248.71 \ mm \ Hg}= \frac{911.6 \ mm \ Hg * 568 \ mL }{248.71 \ mm \ Hg}[/tex]

[tex]V_1 = \frac{911.6 \ mm \ Hg * 568 \ mL }{248.71 \ mm \ Hg}[/tex]

The units of millimeters of mercury (mm Hg) cancel.

[tex]V_1 = \frac{911.6 * 568 \ mL }{248.71 }[/tex]

[tex]V_1 = \frac {517788.8} {248.71 } \ mL[/tex]

[tex]V_1 = 2081.897793 \ mL[/tex]

Let's round to the nearest whole number. The 8 in the tenths place tells us to round the 1 up to a 2.

[tex]V_1= 2082 \ mL[/tex]

The gas initially occupied a volume of 2082 milliliters and choice A is correct.

Consider the reaction between CaCO3 and HCl. Which of the following could speed up the reaction?
I. Increasing concentration of the HCl
II. Increasing size of the CaCO3 pieces
III. Increasing temperature
a) I and III only
b) I, II, and III
c) I only
d) II and III only

Answers

It's d






Jdhxhdhdhhdjddh

Most naturally occurring oxygen (O) isA. oxygen-16 B. oxygen-18 C. oxygen-15 D. oxygen-17

Answers

Option A is correct. Oxygen-16 occurs most naturally among these isotopes.

The three stable isotopes that make up natural oxygen are O-16, O-17, and 0-18, with O-16 having the highest natural abundance (99.762%). The standard atomic weight ranges between [15.99903, 15.99977], depending on the terrestrial source .

Oxygen-16 (16O) is a stable oxygen isotope with 8 neutrons and 8 protons in its nucleus. Its mass is 15.99491461956 u. Oxygen-16 is the most abundant isotope of oxygen, accounting for 99.762% of natural oxygen abundance. 16O has a high relative and absolute abundance because it is a primary product of stellar evolution and a primordial isotope, which means it can be produced by stars that were originally made entirely of hydrogen. The majority of 16O is produced in stars at the end of the helium fusion process; the triple-alpha process produces 12C, which catches an additional 4He to produce 16O. The process of burning neon generates an additional 16O. Oxygen-16 is twice as powerful.

Learn more about oxygen;

https://brainly.com/question/13905823

17. According to Newton's first law, an object in motion will stay in what kind of
motion as long as the net forces acting on it are zero?
A. slowing motion in a straight line
B. accelerating motion in a straight line
C. constant motion in a straight line
D. constant motion in an unpredictable direction

Answers

Answer:

C

Explanation:

According to Newton's first law, an object in motion will stay in motion unless acted upon by an unbalanced force. The option which gives the same meaning is :

constant motion in a straight line

According to Newton's first law, an object in motion as long as the net forces acting on it are zero will stay in:

C. constant motion in a straight line

A constant motion in mechanics is a number that remains constant throughout the motion, effectively placing a restriction on the motion.

What is Newton's first law of motion?The foundation of classical mechanics is made up of the three laws of motion that Newton suggested. These three physical laws. In accordance with the three laws of motion, a body's connection to the forces operating on it and the motion that resulted from those forces are both described. As Galileo's law of inertia, Newton's First Law of Motion is also referred to. If a body is not forced by an outside force to change its condition, it will remain in its state of rest or uniform motion in a straight line. As a factor that has the potential to alter an object's condition, the law defines force and mentions it.In this way, Newton uses the inertia of rest, motion, and direction to describe his first law of motion.A body has an attribute called inertia that makes it resist changes to its state. A body's inertia of translational motion is measured by its mass.

To learn more about Newton's first law of motion, refer to:

https://brainly.com/question/974124

#SPJ2

Preganglionic axons are myelinated; postganglionic axons are unmyelinated.

a. True
b. False

Answers

Answer: True no need for an explanation..

Preganglionic axons are myelinated; postganglionic axons are unmyelinated True

When cyclopentane undergo free-radical substitution with bromine (Br2 /Heat) the product:
a. Bromo cyclopentene
b. Bromo cyclopentane + HBr
c. Bromo cyclopentene + HBr​

Answers

Explanation:

b. Bromo cyclopentane + HBr

Which one of the following compounds will NOT be soluble in water?
A) LiNO3
B) PbS
C) NaOH
D) MgCl2
E) K2SO4

Answers

See the correct answer is b.)PbS

Planet A is an inner planet with no moon and hardly any atmosphere. Planet B is an inner planet with no moon but with a dense atmosphere. Which pair of planets is being described?
A.
Mars and Venus
B.
Mercury and Earth
C.
Mercury and Venus
D.
Mars and Earth

Answers

Answer:

C.

Mercury and Venus

Explanation:

It is because none of them have moons and barely have atmospheres due to how close they are to the sun.

Answer:

mcmmkcmkmec

Explanation:

The high level of pollution in earth's is a planet problem

Answers

Answer:

According to the World Economic Forum, air pollution was found to be the largest current environmental threat to our public health. Up to 52,000 people die every year in the United States alone because of exposure to emissions from power plant emissions.

Write on the principle And other application of
A Named instrument Employed in unlocking frozen glass joints

Answers

Answer:

Glass blower

Explanation:

it's the best instrument

Consider the reaction: NaNO3(s) + H2SO4(l) NaHSO4(s) + HNO3(g) ΔH° = 21.2 kJ

How much heat must absorbed by the reaction system to convert 100g of NaNO3 into NaHSO4(s)?
Please anyone help me out

Answers

The system will absorb 24.9 KJ of heat energy.  

Step 1:

Data obtained from the question

NaNO₃ + H₂SO₄ —> NaHSO₄(s) + HNO₃ ΔH° = 21.2 KJ

Heat absorbed by converting 100 g of NaNO₃ =?  

Step 2

Determination of the mass of NaNO₃ that was converted from the balanced equation.

Molar mass of NaNO₃ = 23 + 14 + (16×3)

= 23 + 14 + 48

= 85 g/mol

Mass of NaNO₃ from the balanced equation = 1 × 85 = 85 g

Thus, 85 g of NaNO₃ were converted from the balanced equation.

Step 3

Determination of the heat absorbed by converting 100 g of NaNO₃.

From the balanced equation above,

When 85 g of NaNO₃ were converted, 21.2 KJ were absorbed by the system.

Thus, the conversion of 100 g of NaNO₃ will cause the system to absorb = [tex]\frac{100 * 21.2}{85} =[/tex] 24.9 KJ of heat energy.

Therefore, the system will absorb 24.9 KJ of heat energy.

Learn more: https://brainly.com/question/13728390

Other Questions
Help Please I willMark brainliest I cant figure out which formula goes with which sequence. Help. Please???1st sequence:1,3,9,27,. What is the formula?2nd sequence:400,200,100,50,What is the formula?3rd sequence:4,8,16,32,What is the formula?4th sequence:400,100,25,6.25,What is the formula?5th sequence:1,5,25,125,What is the formula?6th sequence:1000,500,250,125,What is the formula?7th sequence:2,10,50,250What is the formula?I need to know the correct geometric sequence formula for each of these sequences. Thanks!!! FInd the volume of the figure Superficial similarities in structures that have the same function can seem like they are evidence of a common ancestor, but they are not. An example of this is the convergent evolution of wings in insects as well as in birds. What are these types of structures called ? : , , , , , , , , , , , , , , , , , , , , , , , , , , , Write a sentence for each vocabulary word below:nutrientnutritionwellnesshospitalitycomfort foodsstress hormonepalateself-esteemcritical thinkingverbal communicationnonverbal communicationleadershipmanagement Write a letter to your friend who is studying in another school describing about your e-Learning (Online) Classes run by our school during this pendamic. Along the inferior surface of the liver are several structures that collectively resemble the letter H. The ______ and the round ligament of the liver form the vertical superior parts of the H; the inferior vena cava and the ligamentum ______ form the vertical inferior parts. 6. Using a base year and calculating each future amount as a percentage of the base year amount is called avertical analysis.common size.horizontal analysis ratio analysis. what are the core basics of ideology A man earns RS.95 in a day how much does we earn in 18 days What is the solution to each system3) y=3x+1 3x+y=14) y=2x+1 y=2x+45) y= -5x+1 y=2x+4 As leader of the Mughal Empire, Akbar the Great won the support of hissubjects by:A. eliminating laws that discriminated against Hindus.B. forcing European merchants to leave Mughal lands.C. ending the empire's many expensive foreign wars.D. requiring all Muslim subjects to become Shias. Energy transformation and production in the cell are the functions ofwhich organelles? Identify the adjective are named their kind 1- I am tired2-thats my pen3- preeti is witty 4- I ate some rice5-this is his room6-we bought French cheese What are the basic points to be considered while running the occupation? for each of them PLZ HELP ME A single bacterial cell divides to make new bacterial cells. Which of the following is true of this kind of reproduction? A Two parents come together to produce offspring with different characteristics B. Two parents come together to produce offspring that are exact copies of one parent C One parent produces offspring that are exact copies of the parent D. One parent produces of sening with different charactenstes SUERT in a 41-49 right triangle, the hypotenuse is 28.83 centimeters. if cos 41= 0.7547, find the length of the side opposite the 49 angle. Estimate your answer to three decimal places Alter the American Revolution, why did other nations look to the United States as a model nation?The United States was a representative democracyThe United States forang its colonial rulers to leaveThe United States was able to maintain its independence,The United States balanced the interests of the central and local governments,Save and itMO Show that:a) The 2nd differences in the following row are constant and calculate:b)Tn4; 7; 12; 19;....-1; 2; 7; 14;....-2;-8; -18; -32; ...