Answer:
Reproducible by other scientists
The personal opinion of the scientist
Using vanable conditions for each test
Explanation:
Which sentence describes existing cells?
All cells, once formed, continue to live forever.
All cells come from previously existing cells.
All the cells that are on Earth have always been here.
All cells develop from the remains of other cells.
2(3a-3)-2(a-2)=3
thank you
Answer:
6a - 6 - 2a + 4 = 3
4a - 2 = 3
4a = 3 + 2
4a = 5
a = 5/4
hope that helps ✌
Write a hypothesis that answers the lesson
question, "While observing a chemical reaction,
how can you tell which reactant is limiting?"
Hypothesis: If a substance is the limiting
reactant, then..
Answer:
the reaction will come to a halt and the other reactant will still be present.
Write an equation to show how perchloric acid, HClO4, reacts with water. Include states of matter in your answer.
Since perchloric acid is a strong acid, it will dissociate completely, along with water. The products will be Perchlorate ions and Hydronium ions after the Perchloric acid gave away its proton and water, acting as a base, accepted that abandoned proton.
Which of the following is an example of a chemical change?
A. Sugar breaking down into water and carbon when it is heated
B. A sugar cube being crushed by a spoon
C. Sugar mixing with red food coloring and forming a red solid
D. A sugar cube dissolving in water as the water is stirred
Answer:
I think its sugar breaking down into watee and carbon when it is heated
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
can you solve this.
I need it.
:) :):)
Answer:
12
45
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are standard electrode potential and standard hydrogen potential same?
Answer:
Potentials of any other electrodes are compared with that of the standard hydrogen electrode at the same temperature. Hydrogen electrode is based on the redox half cell: 2 H+(aq) + 2 e− → H2(g)..
if any 1 studying 11th can u plz send me the chemistry notes for chapter 2 STRUCTURE OF AN ATOM lesson
plz send me honestly cause i have exam day after tommorow .so plz send unwanted answer
I BEG U
Answer:
What
You cant just send notes you also have to say where you are and which book you are using because others are different
What happens when a metalloid gets heated up?
A: It acts as an insulator and slows the flow of electrons.
B:It blocks the flow of all electrons.
C:It conducts more electricity, allowing electrons to move more freely.
D:It becomes too dangerous for electricity to flow through it.
Answer:
it becomes too dangerous for electricity to flow through it
One the first chemistry test. 12 students got As, 18 students got Bs, and 20 students got Cs.
a. What is the percentage of students received Bs.
b. What is the percentage of students who received Cs?
Express your answer to the ones place.
Answer:
A. 36 percent recieved Bs
B. 40 percent of students received Cs
Explanation:
Amount of students: 12+18+20=50
Students with Bs: (18÷50) x 100 = 36%
Students with C's: (20÷50) x100 = 40%
On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40
What is the percentage of students received B and C?In mathematics, a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign %. A percentage is a dimension less unit and it has no unit.
In above question 12 student got A, 18 student got B, and 20 student got C.
So total number of student = 12 + 18 + 20 = 50.
Then the percentage of students received B is as follows:-
Percentage of students who got B = (student who got B/Total number of student) X 100.
=(18/50) X 100
= 36%
Now percentage of students who got C = (No of students who got C/Total students)X100
=(20/50) X 100
=40%.
Therefore,On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40 percentage of students who got B is 36% and percentage of students who got C is 40%
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Convert 50 m to mm
using the method of dimensional analysis
Answer:
Explanation:
meters has to go on the bottom of the bracket used for conversion
50m [ 1000 mm / 1 m]= 50000 mm The meters cancel
Choose the incorrect statement. Question 5 options: A reaction intermediate has fully formed bonds. A reaction intermediate is produced and used up during the reaction. An activated complex has partially formed bonds. A transition state and a reaction intermediate are the same.
Answer:
Option D) A transition state and a reaction intermediate are the same.
Explanation:
A transition state and a reaction intermediate are the not same. The transition state represents the highest energy in the steps of a reaction, whereas an intermediate, on the other hand, is represented by the lowest energy minimum in a reaction.
difference between Nitrogen 1 oxide and Oxygen
Answer:
one atom of oxygen is not equal to oxygen
Which atom would be neutral?
1an oxygen atom with 16 electrons, 18 protons, and 16 neutrons
2an oxygen atom with 4 electrons, 6 protons, and 4 neutrons
3an oxygen atom with 9 electrons, 8 protons, and 8 neutron
4an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
A proton has a positive charge and an electron has a negative charge. Magnitude of both of these charges is same. So, we need the same number of electrons and protons to make the atom neutral.
Neutron is neutral, so we can safely ignore it in this question.
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
Determine the grams of sodium chloride produced when 10 g of sodium react with 10 grams chlorine gas according to the equation 2Na + Cl2 = 2 NaCl
Answer:
16 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Identify the limiting reactant
The theoretical mass ratio (TMR) of Na to Cl₂ is 46:71 = 0.65:1.
The experimental mass ratio (EMR) of Na to Cl₂ is 10:10 = 1:1.
Since EMR > TMR, Cl₂ is the limiting reactant
Step 3: Calculate the mass of NaCl produced
The theoretical mass ratio of Cl₂ to NaCl is 71:117.
10 g Cl₂ × 117 g NaCl/71 g Cl₂ = 16 g NaCl
Describe the formation of oxygen molecule
Answer:
oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .
write an importance of endothermic reactions
Answer:
the uses of exothermic reactions are:
1) lighting of stove
2) self heating cans
3) hand warmers
4) in some case exothermic process can be used to cook food such as rice (by adding calcium oxide to water heat is evolved and it helps to cook food )
Explanation:
hope this helps you pls mark me as brainilst
which type of model best represents simple molecules?
> ribbon
> wire
> Lewis dot
> structural formula
Answer:
Lewis dot
Explanation:
It's a very simplified representation of the valence shell electrons in a molecule.
The correct answer is Lewis dot.
A Lewis dot structure of a molecule is a structure in which the valence electrons of the molecule are represented using dots.
It is usual to seek a simple representation for simple molecules that explains in part, the properties of the molecule.
Such a representation must show the valence electrons in the molecule. A simple representation that can do this is the Lewis dot structure of molecules. The Lewis dot structure of NO2 molecule is shown in the image attached to this answer.
It was introduced by G.N Lewis and can be successfully used to represent many simple chemical molecules.
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Which metal can replace another metal in a reaction?
A. Any metal on the list can replace any other metal also on the list.
B. A metal on the activity series list will replace one that is not on the
list.
C. A metal lower on the activity series list will replace one that is
higher
D. A metal higher on the activity series list will replace one that is
Tower
Answer:
D
Explanation:
The atoms of the more reactive metal push their electrons on to ions of the less reactive metal.
Which of the following would be most likely to form a +2 cation?
The Periodic Table
A. Sulfur (S)
B. Calcium (Ca)
C. Chlorine (CI)
O D. Potassium (K)
Calcium because group 2 metals are all 2+ cations
Josefina and Raul were comparing how sound moves through various mediums and how charge moves through conducting wires. They performed experiments to find out if the factors that determine the speed of sound are the same as those that determine the flow in a circuit. What did they find? Describe two things that they found. For each, explain how the speed of sound and flow of current are affected
They found that difference occurs in the speed of both sound and charges occur due to the difference in the type of medium.
Sound and charges needs specific medium for faster movement i.e. sound moves faster in solid as compared to liquid and gas whereas charges moves faster and easily in gold due to lower resistance which is followed by copper. Sound can move from solid, liquid and gases whereas charges move only in solid metal in which free electrons are present. The speed of sound and flow of current are affected due to difference in the arrangement of atoms in solid, liquid and gas.
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A mineral sample has a mass of 35 g. When it is dropped into a graduated cylinder with 25mL of water, the volume of the water rises to 35 mL. Using this data, determine the density of the sample.
Answer:
3.5g/ml
Explanation:
density=mass/volume
the mass of the mineral we have been given to be 35g
and it's volume is found by subtracting the initial volume from the final volume which is 35ml-25ml=10ml
Answer:
[tex]\boxed {\boxed {\sf 3.5 \ g/mL}}[/tex]
Explanation:
The density of an object is the mass per unit volume, so the formula is:
[tex]\rho= \frac {m}{v}[/tex]
We know the mass of the mineral sample is 35 grams.
We have to calculate the volume. The volume was found using water displacement. An amount of water was put in a graduated cylinder, then the object was dropped in. The volume is the difference between the final water level and the initial water level.
v= final water - initial water v= 35 mL - 25 mL v= 10 mLNow we know the mass and volume of the mineral sample.
m= 35 g v= 10 mLSubstitute the values into the formula.
[tex]\rho= \frac{35 \ g}{10 \ mL}[/tex]
Divide.
[tex]\rho = 3.5 \ g/mL[/tex]
The density of the mineral sample is 3.5 grams per milliliter.
How does a scientific theory differ from a guess or an opinion?
Answer:
Scientific theory differs from a guess or opinion because a scientific theory is a system of ideas that explains many related observation and is supported by a large body of evidence acquired through scientific investigation while guesses and opinions may not reliably predict an outcome, have evidence to back up the theory
Explanation:
A scientific theory is defined as the explanation of the universe and the natural sciences. It differs from opinions and guesses as they are supported by observations and evidence.
What is a scientific theory?A scientific theory has been a detailed description and explanation of the natural sciences and the universe that are studied and developed with the help of the hypothesis and the facts.
It relies on the scientific method to conclude the accountability by observing, estimating, and then concluding the matter with supportive evidence.
It differs from guess and opinions as it involves investigations, research, evidence to back the idea, whereas the latter and are not reliable and lacks evidence.
Therefore, scientific theory differs from opinion.
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what is cytoplasm ? what does it contain?
Answer:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm.
Answer:
Explanation:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm. ...
yall what do ya think shaped ya feelings bout science classes?
I was interested in science when I first saw a diagram of Solar system in my sister's geography book. At that time I was in Senior Kindergarten and she was in 6th grade. At first, I was just interested in space, universe and black holes stuff, but then as I started learning more, I realised how amazing other branches of science are too. They are so systematic. What encourages me to learn more are the gaps in science, its mysteries, I wish to uncover them one day, and for that I am preparing myself. When I am in a science class, I try to imagine where can I apply this knowledge in my day to day life, and my teachers are fascinated when I ask them if this principle is responsible for this phenomena. I love it very much. I like Physics the most, but other branches are great too.
A reaction happens quickest during:
A. The beginning of the reaction
B. It is constant throughout the reaction
C. The end of the reaction
D. The middle of the reaction
The reaction is the formation of the product from the reactants. A reaction happens quickest during the beginning of the reaction. Thus, option A is correct.
What are the factors affecting the reaction rate?The reaction rate is the pace at which the reaction takes place and the breakdown or the combination of the reactants to produce the products. The rate of reaction depends on the concentration of the reactants.
The concentration of the reactants is in direct proportion with the rate as at the beginning of a reaction there is a higher amount of substance present than at the end.
As the reaction proceeds, the reactants get consumed and their concentration decreases. As there is a decrease in concentration the rate of the reaction converting and producing the products also decreases.
Therefore, option. the rate of reaction is fast at the beginning.
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(b)
Huiting wanted to find out the hardness of two materials H and F. She used a
rounded object made of material G and forced it into each material with the
same force. The results of her experiment are shown below.
rounded object of
material G
rounded object
of material G
3 mm
1 mm
object of
material H
object of
material F
List materials F, G, H in increasing order of hardness. Explain your answer.
[2]
Object named H is harder than Object F due to its thickness.
The object of material H is harder than the object of material F due to the difference in thickness. The thickness of Material Object H is 3 millimeters compared to Material Object F which is 1 millimeter thick, so applying the same amount of force on both objects, Material Object H does not show any change in its structure while on the other hand, the shape of the object F changes due to a lower hardness.
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Which of the following represents an endothermic reaction?
Select one:
a. S(s) +O2(g) → SO2(g) ΔH = -297kJ
b. 2NO2(g) → N2(g) + 2O2(g) + 33.8kJ
c. N2(g) + 2O2(g) + 90.4kJ → 2NO2
d. N2H4(g) + O2(g) → N2(g) +2H20(g) + 627.6 kJ
B because decomposition reactions are often caused by the application of heat to break up the bonds within the molecules, which will form the molecules that made up the decomposed molecule.
Our burning of fossil fuels for energy poses several different problems. Describe what is generally considered the biggest problem and the main reason for using alternatives.
PLEASE HELP!!
Can someone plz help me :<
Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens
Explanation:
