Answer:
Half life is the time taken by a radio active isotope to reduce by half of its original amount. Radium-226 has a half life of 1602 years meaning that it would take 1602 years for a mass of radium to reduce by half.
Number of half lives in 9612 years = 9612/1602 = 6 half lives
New mass = Original mass x (1/2)n where n is the number of half lives.
Therefore, New mass= 500 x (1/2)∧6
= 500 x 0.015625
= 7.8125 g
Hence the mass of radium after 9612 years will be 7.8125 grams.
Explanation:
Answer:
[tex]\boxed {\boxed {\sf 6.25 \ grams}}[/tex]
Explanation:
We are asked to find the mass of a sample of radium-226 after half-life decay. We will use the following formula:
[tex]A= A_o *\frac{1}{2}^{\frac{t}{h}}[/tex]
In this formula, [tex]A_o[/tex] is the initial amount, t is the time, and h is the half-life.
For this problem, the initial amount is 200 grams of radium-226, the time is 8,000 years, and the half-life is 1,600 years.
[tex]\bullet \ A_o= 200 \ g \\\\bullet \ t= 8,000 \ \\\bullet \ h= 1,600[/tex]
Substitute the values into the formula.
[tex]A= 200 \ g * \frac{1}{2} ^{\frac{8.000}{1,600}[/tex]
Solve the fraction in the exponent.
[tex]A= 200 \ g * \frac{1}{2}^{5}[/tex]
Solve the exponent.
[tex]A= 200 \ g *0.03125[/tex]
[tex]A= 6.25 \ g[/tex]
In addition, we can solve this another way. First, we find the number of half-lives by dividing the total time by the half-life.
8,000/1,600= 5 half-livesEvery half-life, 1/2 of the mass decays. Divide the initial mass in half, then that result in half, and so on 5 times.
1. 200 g/2= 100 g2. 100 g / 2 = 50 g3. 50 g / 2 = 25 g 4. 25 g / 2 = 12.5 g5. 12.5 g / 6.25 gAfter 8,000 years, 6.25 grams of radium-226 remains.
the reaction of solid carbon with oxygen gas to form carbon dioxide gas.
Answer:
When solid carbon reacts with oxygen molecule, it leads to the production of carbon dioxide gas. The chemical equation for the formation of carbon dioxide follows: By Stoichiometry of the reaction: 1 mole of solid carbon reacts with 1 mole of oxygen gas to produce 1 mole of carbon dioxide gas.
Explanation:
Solid carbon reacts with oxygen gas to form carbon dioxide gas.
The balanced chemical equation for this reaction:
c(s)+o2(g)+co2(g)
The decrease in the water table due to overuse of water.
Answer: Groundwater and surface water are connected. When groundwater is overused, the lakes, streams, and rivers connected to groundwater can also have their supply diminished. Land subsidence occurs when there is a loss of support below ground. This is most often caused by human activities, mainly from the overuse of groundwater, when the soil collapses, compacts, and drops.
Hope it Helps. :)
calculate the volume of 20.5g of oxygen occupied at standard temperature and pressure.what the volume
Answer :
volume of a gas = weight * 22.4 l / gram molecular weight
volume of o2 = ?
weight given = 20.5 g
gram molecular weight of oxygen = 32 (because of 2 oxygen atoms )
volume of oxygen = 20.5 * 22.4 / 32
volume of oxygen = 14.35 liters
Explanation:
hope this helps you
if wrong just correct me
An outdoor gear company develops a new type of fabric that works with electricity to warm the body without interfering with motion like heavy jackets do. Research biologists, studying life in extremely cold conditions on the polar ice caps, begin wearing the new fabric because it helps them work more comfortably, and they find it increases their productivity.
What best describes how the processes of scientific investigation and technological design are involved in this situation?
The clothing company conducted a scientific investigation to communicate results to researchers, who then used the knowledge in a technological design.
The clothing company conducted a scientific investigation to produce a product that researchers could then test while designing new technology.
The clothing company used technological design to create a product that helped aid researchers conducting a scientific investigation.
The clothing company designed a new technology that provided information researchers needed in order to continue with their scientific investigation.
Answer:
C: The clothing company used technological design to create a product that helped aid researchers conducting a scientific investigation.
Explanation:
I just did the assignment on EDGE2020 and it's 200% correct!
Also, heart and rate if you found this answer helpful!! :) (P.S It makes me feel good to know I helped someone today!!) :)
In what areas of the periodic table do you find the most highly reactive elements?
Answer:
The elements toward the bottom left corner of the periodic table are the metals that are the most active in the sense of being the most reactive.
The most highly reactive elements are typically found at the far left (Group 1) and far right (Group 17) of the periodic table.
Highly reactive elements in the periodic tableGroup 1 elements, also known as alkali metals, are located on the far left of the periodic table. They have one electron in their outermost energy level and are highly reactive due to their tendency to lose that electron to achieve a stable electron configuration. This makes them very reactive with water and other substances.
Group 17 elements, known as halogens, are located on the far right of the periodic table. They have seven electrons in their outermost energy level and are highly reactive due to their strong tendency to gain one electron to achieve a stable electron configuration. This makes them reactive with metals and other elements.
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A sample of a compound is found to consist of 0.44g H and 6.92g O what’s its formula
Answer:
Explanation:
H = 0.44/1.01 = 0.4356
O = 6.92/16 = 0.4319
This gives a 1:1 ratio. So the closest thing you could say is the formula is 0H
Going to your chemical storage room, you could justify that it is H2O2 or hydrogen peroxide. The question needs one more fact to make the answer certainty.
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
Answer:
gahwidsuacsgsuacayau1joagavahiq8wtw8quavakiafabajozyavqhaigavayquata
Explanation:
vahaiqgahiavavqugafayqigqvsbjsiagwyeiwvvs
Explain the working principle of a clinical thermometer
Answer:
A clinical thermometer is a thermometer used to measure human body temperature. Most made in the 20th century are mercury-in-glass thermometers. They are accurate and sensitive, having a narrow place where the mercury level rises very fast. A kink in the tube stops the mercury level from falling on its own.
There are three isotopes of carbon. They have mass number of 12, 13 and 14. The average atomic mass of carbon is 12.0107 amu. What does this say about the relative abundances of the three isotopes?
Answer:
lots more of the carbon 12 than the others
havent calculated it percentage-wise but you can see its very close to 12 meaning it is of far greater abundance that carbon 13 and 14
Explanation:
Question 5 of 10
Which statement describes the law of conservation of energy?
A. When an energy transformation happens, no energy is destroyed
or created.
B. There is only one form of energy.
C. Energy can only change from nuclear energy to chemical energy.
D. The total energy in a system can only increase.
Answer:
A
Explanation:
A option is correct .
you cannot create energy neither you can destroy it but you can only convert into other form
Which one of these four atoms has the most neutrons?
O A.
79
Se
34
B.
80
Br
35
OC.
73
Ge
32
84
Kr
36
O D.
Answer:
kr
Explanation:
it is radioactive so it loss electron due to which it jas most neutons
how do we use the circle of fifths
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.
Given the equation representing a nuclear reaction in
which X represents a nuclide:
232Th → He + x
Which nuclide is represented by X?
A) 236
B) 228
Ra
SS
C) 236
Ra
92
U
92
D) 228
.
Ss U
The nuclide represented as X is thorium and this is an alpha decay.
The equation shown represents an alpha decay. In an alpha decay, an alpha particle is given off.
The atomic number of the parent nuclide is greater than that of the daughter nuclide by two units while the mass number of the parent is greater than that of the daughter nuclide by four units.
Hence the equation occurs as follows;
[tex]\frac{232}{92} Th ------> \frac{228}{88} Ra + He[/tex]
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L-histamine is an essential amino acid.
a. True
b. False
Answer:
Hmmm
Histamine is gotten from the De-carboxylation of Histidine
I'd go with false.
Histamine is NOT an essential amino acid
Option B is legit!
H2SO4 ????????????????
Explanation:
Sulfuric Acid (H2SO4) is a strong mineral acid that has is colorless when pure. This chemical is used as a chemical intermediate to manufacture other chemicals and cleaning metal surfaces. The formula for sulfuric acid is H2SO4. The molar mass of sulfuric acid is 98.07848 g mol.
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
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
Answer:
maybe number b is correct. ...thank you
The equilibrium constant K changes with changes in
the temperature.
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
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: 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
Data obtained from the question
NaNO₃ + H₂SO₄ —> NaHSO₄(s) + HNO₃ ΔH° = 21.2 KJ
Heat absorbed by converting 100 g of NaNO₃ =? Step 2Determination 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 3Determination 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.
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Different vinegars can be 5-20% acetic acid solutions and have been used for medicinal purposes for thousands of years. If a person takes 2.0 tablespoons of vinegar a day and the Molarity of the vinegar is .84 M, then how many grams of acetic acid (HC2H3O2) will be consumed? 1 Tablespoon is 15 mL.
.013 g
.026 g
.76 g
1.5 g
Answer:
1.5g
Explanation:
Remember that Molarity = (#moles of solute)/(#liters of solution)
This problem informs us that the Molarity of the vinegar is 0.84 and that the solution is 15mL.
First let's get your SI units to the correct ones.
15mL (1L/1000mL) = 0.015L
Molarity = (#moles of solute)/(#liters of solution) ~
(Molarity)(#liters of solution) = #moles of solute
(0.84M)(.015L) = 0.0126moles of acetic acid per tablespoon
2 tablespoons a day = 0.0126moles*2 = 0.0252 moles of acetic acid.
Now that we have the # of moles of acetic acid we need to get our answer into grams. The molecular weight of HC2H3O2 is 60g/mole.
0.0252mole HC2H3O2 (60g HC2H3O2/1mole HC2H3O2) = 1.512g ~ 1.5g HC2H3O2.
The big bang theory suggests that the origin of the universe began with
that exploded and
expanded.
Answer:
Yes?
Explanation:
If you're asking whether or not that's true, then the Big Bang suggests a way the universe might have formed, so yes it's true
Answer:
A star
Explanation:
Why is it difficult to classify dissolving as simply a physical or a chemical change? (1 point)
O Some substances keep the same molecular structure when they break down, and others do not.
O Some substances release energy when they dissolve, and some absorb energy.
O Some substances taste the same after they dissolve, and others do not.
O Some substances keep the same color when they dissolve, and others do not.
Answer:
It is difficult because of C
Explanation:
The correct answer is:Some substances keep the same molecular structure when they break down, and others do not.
Some substances change their form when they dissolve and some do not. Dissolution can sometimes be regarded as a sort of reaction between a chemical substance and water.
Usually, we can consider dissolution of a substance in water as a sort of chemical reaction for some substances. For instance, an ionic substance interacts with water to form ions. similarly, some salts become hydrolysed in water and give acidic/basic solutions as result of that.
However, some substances do not interact with water upon dissolution. They rather remain as molecular entities because they are not composed of ions.
We can see that some substances keep the same molecular structure when they break down, and others do not keep the same molecular structure when they dissolve hence it is difficult to classify dissolving as a physical or a chemical change.
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What is the change in the freezing point of a solution made by dissolving 14.7 g of
C6H1206 into 150 ml of water? Answer in 2 decimal.
The density of water is 1.00 g/ml and and Kf = 1.86 °C/m
The change in freezing point is 1.02°C
The change in the freezing point (ΔTf) is calculated from the following equation:
ΔTf = i x Kf x m
Given:
i = 1 (Van't Hoff factor, is equal to 1 because the solute is a nonelectrolyte)
Kf = 1.86°C/m (Freezing point constant of the solvent)
m = molality
We have to calculate the molality (m), which is equal to the moles of solute in 1 kg of solvent:
m = moles solute/ kg solvent
The solute is C₆H₁₂O₆. Thus, we calculate the moles of solute by dividing the mass into its molecular weight (Mw):
Mw(C₆H₁₂O) = (12 g/mol C x 6) + ( 1 g/mol H x 12) + (16 g/mol O x 6) = 180 g/mol
moles solute = mass C₆H₁₂O/Mw(C₆H₁₂O) = 14.7 g/(180 g/mol) = 0.082 mol
The solvent is water. Its mass (in kg) is obtained from the volume and the density, as follows:
kg solvent = V x density = 150 mL x 1.00 g/mL x 1 kg/1000 g = 0.15 kg
Now, we calculate the molality (m):
m = moles of solute/kg solvent = 0.082 mol/(0.15 kg) = 0.546 m
Finally, we calculate the change in freezing point:
ΔTf = i x Kf x m = 1 x 1.86°C/m x 0.546 m = 1.02°C
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which list only includes terms that describe... both questions please
The terms that describe sodium atom are;
AtomelementPure substanceThe terms that describe propane gas are;
MoleculeCompoundPure substanceSodium can be described as an element found in the periodic table. Sodium can also be described as an atom as in when we make the statement; 'an atom of sodium'. Sodium can also be regarded as a pure substance as in when we are referring to a substance composed only of sodium atoms.
On the other hand, propane gas can be regarded first as a compound because it is a combination of elements that are chemically combined together. We can also refer to 'a molecule of propane gas' since the substance is molecular in nature. Also, the pure gas (containing no impurity) can be regarded as a pure substance.
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what happened when potassium chloride is added to silver nitrate solutions . there no reaction B two soluble salts are formed C two insoluble salts are formed D. one soluble salts and one insoluble salts are formed.
Answer:
D. One soluble and one insoluble salts are formed
Explanation:
6. Plants play a vital role in the environment because photosynthesis
ОООО
A. uses atmospheric oxygen and carbon dioxide to produce sugars and water.
B. uses atmospheric oxygen and water to produce carbon dioxide and water.
C. uses atmospheric carbon dioxide and water to produce sugars and oxygen.
D. uses atmospheric oxygen to produce sugars and water.
Plants play a vital role in the environment because photosynthesis uses atmospheric carbon dioxide and water to produce sugars and oxygen. Option C is correct.
Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose (sugar). This process occurs in the chloroplasts of plant cells and requires the presence of sunlight, carbon dioxide (CO₂), and water (H₂O).
During photosynthesis, plants absorb carbon dioxide from the atmosphere through tiny openings called stomata in their leaves. At the same time, they take in water from the soil through their roots. Through a series of complex chemical reactions, the energy from sunlight is used to combine carbon dioxide and water, resulting in the production of glucose (sugar) and the release of oxygen (O₂) as a byproduct.
This process is represented by the equation:
6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ (glucose) + 6O₂
Plants use the glucose produced through photosynthesis as a source of energy for various metabolic processes and growth. The released oxygen is essential for the survival of other organisms, including humans, as it is used in cellular respiration to release energy from glucose.
Hence, C. is the correct option.
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Which molecule is butane?
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,
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1.46 mol sample of nitrogen gas at a temperature of 14.0 °C is found to occupy a volume of 23.7 liters. The pressure of this gas sample is mm Hg
Explanation:
Since there are no gas constant with the unit of mmHg, you just have to use the gas constant for atm, and then convert that into mmHg
Which one is more acidic, Chloroacetic acid or Bromoacetic acid? And why?
Chloroacetic acid is stronger.
This is because it contains (more electronegative) chlorine atoms in place of (less electronegative) hydrogen atoms.
