Answer:
List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass
Explanation:
is a physiologist. Which would most likely be the main focus of her studies?
how atoms bond to form different kinds of matter
how subatomic particles interact and make up atoms
how certain molecules affect the function of the human heart
how the structure of the human brain may differ between humans
How many moles are contained in 127 grams of lead?
Answer:
18.015
Explanation:
Which of the following is a completely elastic collision? A. a ball rebounds against a wall, reversing its direction, but at only half the speed. B. Two balls collide, stick to each other, and move together after the collision. C. Two balls collide and move at a right angle to each other after the collision at a reduced speed. D. Two balls collide head on, each reversing its direction and traveling at half the speed. E. A ball with velocity v collides with a ball at rest; after the collision the first ball is at rest and the second ball has velocity v. I will mark brainliest
Answer:
Answer E.
For a collision to be completely elastic, there must be NO LOSS in kinetic energy.
We can go through each answer choice:
A. Since the ball rebounds at half the initial speed, there is a loss in kinetic energy. This is NOT an elastic collision.
B. A collision involving sticking is an example of a perfectly INELASTIC collision. This is NOT an elastic collision.
C. A reduced speed indicates that there is a loss of kinetic energy. This is NOT elastic.
D. The balls traveling at half the speed after the collision indicates a loss of kinetic energy, making this collision NOT elastic.
E. This collision indicates an exchange of velocities, characteristic of an elastic collision. We can prove this:
Let:
m = mass of each ball
v = velocity
We have the initial kinetic energy as:
KE = \frac{1}{2}mv^2 + 0 = \frac{1}{2}mv^2KE=21mv2+0=21mv2
And the final as:
KE = 0 + \frac{1}{2}mv^2 = \frac{1}{2}mv^2KE=0+21mv2=21mv2
Answer:
E
Explanation:
hope this helps
Give reason. When the tip of a plant is cut, it does not grow tall.
Answer: The growth of the plant decides on the presence of plant hormone, auxin which develops in the roots and shoots. Auxins change the rate of elongation in plant cells, controlling how long they become. So, if the tips are removed, there is no auxin made and growth of the plant stops.
NEED ASAP WILL GIVE BRAINLIST
Answer:
It have 31 electrons
It have 31 electrons
How many grams are in 2.0 × 1024 atoms of C?
Answer:
2.24 i think.
Explanation:
The decomposition of ethanol (C2H5OH) on an alumina (Al2O3) surface C2H5OH1 g2 h C2H4 1 g2 1 H2O1 g2 was studied at 600 K. Concentration versus time data were col- lected for this reaction, and a plot of [A] versus time resulted in a straight line with a slope of 24.00 3 1025 mol/L s. a. Determine the rate law, the integrated rate law, and the value of the rate constant for this reaction. b. If the initial concentration of C2H5OH was 1.25 3 1022 M, calculate the half-life for this reaction. c. How much time is required for all the 1.25 3 1022 M C2H5OH to decompose?
The rate constant for the decomposition of ethanol on an alumina surface is 24.00 × 10²⁵ M.
The rate law is: rate = 24.00 × 10²⁵ M/s
The integrated rate law is: [C₂H₅OH]t = [C₂H₅OH]₀ - 24.00 × 10²⁵ M/s × t
If the initial concentration of C₂H₅OH was 1.25 × 10²² M, the half-life is 2.60 × 10⁻⁵ s.
The time required for all the 1.25 × 10²² M C₂H₅OH to decompose is 5.21 × 10⁻⁵ s.
Let's consider the decomposition of ethanol on an alumina surface.
C₂H₅OH(g) ⇒ C₂H₄(g) + H₂O(g)
The plot of [A] vs time (t) resulted in a straight line, which indicates that the reaction follows zero-order kinetics.
The slope, 24.00 × 10²⁵ M/s, represents the rate constant, k.
What is zero-order kinetics?It is a chemical reaction in which the rate of reaction is constant and independent of the concentration of the reacting substances
The rate law for zero-order kinetics is:
rate = 24.00 × 10²⁵ M/s
The integrated rate law for zero-order kinetics is:
[C₂H₅OH]t = [C₂H₅OH]₀ - 24.00 × 10²⁵ M/s × t
What is the half-life?Is the time for the amount of substance to decrease by half.
If the initial concentration of C₂H₅OH was 1.25 × 10²² M, we can calculate the half-life [t(1/2)] using the following formula.
t(1/2) = [C₂H₅OH]₀ / 2 × k
t(1/2) = (1.25 × 10²² M) / 2 × (24.00 × 10²⁵ M/s) = 2.60 × 10⁻⁵ s
We can calculate the time required for all the 1.25 × 10²² M C₂H₅OH to decompose using the integrated rate law.
[C₂H₅OH]t = [C₂H₅OH]₀ - 24.00 × 10²⁵ M/s × t
0 M = 1.25 × 10²² M - 24.00 × 10²⁵ M/s × t
t = 5.21 × 10⁻⁵ s
The rate constant for the decomposition of ethanol on an alumina surface is 24.00 × 10²⁵ M.
The rate law is: rate = 24.00 × 10²⁵ M/s
The integrated rate law is: [C₂H₅OH]t = [C₂H₅OH]₀ - 24.00 × 10²⁵ M/s × t
If the initial concentration of C₂H₅OH was 1.25 × 10²² M, the half-life is 2.60 × 10⁻⁵ s.
The time required for all the 1.25 × 10²² M C₂H₅OH to decompose is 5.21 × 10⁻⁵ s.
Learn more about zero-order kinetics here: https://brainly.com/question/13314785
In the urea molecule, (NH2)2CO, both nitrogen atoms are bonded to the carbon atom. Each nitrogen atom has a lone pair. The molecular geometry is
Answer:
There are two -NH2 groups around the C=O. bond in the urea molecule structure. There are one lone pairs on each nitrogen atoms and two lone pairs on oxygen atom.
The molecule urea that the molecular geometry of the nitrogen atoms is tetrahedral.
What is molecular geometry?The term molecular geometry has to do with the arrangement of atoms around the central atom. On this case, we are looking at the arrangement of atoms around nitrogen.
We can see from the molecule urea that the molecular geometry of the nitrogen atoms is tetrahedral.
Learn more about urea:https://brainly.com/question/21133305
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A chemical reaction produces formaldehyde, with a chemical formula of CH2O. Carbon is in Group 4A, oxygen is in Group 6A, and hydrogen is in Group 1A on the periodic table. In one to two sentences, describe the bonds in a molecule of formaldehyde in terms of valence electrons.(2 points)
This problem is providing a comparison on the atoms forming formaldehyde, CH₂O, in terms of the groups they are in, C in group 4A, O in group 6A and H in group 1A, and it is asking for a description about the bonds once they are bonded in a formal Lewis dot structure.
In such a way, the attached file shows the Lewis dot structure, in which we can find two bonds between the two hydrogen atoms and the carbon one, and also, a double bond between carbon and oxygen.
The aforementioned is explained by bearing to mind the concept of octet, which states that elements in groups 4A, 5A, 6A and 7A are able to complete 8 valence electrons after bonding.
Thus, since carbon is in group 4A we infer it needs 4 more electrons to complete the octet, and that is achieved due to the 4 bonds it is having with the two hydrogen atoms and double bond with the oxygen atom.
In addition, since oxygen is in group 6A, we infer it needs two more electrons to complete its octet, which is attained via the double bond it has with the carbon atom. For hydrogen, however, it can complete one bond at maximum, because it is in group 1A, which means it can complete two valence electrons after bonding.
Learn more:
https://brainly.com/question/10535983https://brainly.com/question/21089350Answer:
Ok I seen the answers on here talk about over complicated lol
Explanation:
CH2O
1 carbon atom
2 hydrogen atoms
1 oxygen atom
then is born CH2O aka formaldehyde : )
What's similar about the valence electrons of Carbon and Silicon?
Answer:
Explanation: Carbon and silicon BOTH come from Group 14 of the Periodic Table , i.e. both formally have the same number of valence electrons, 4 such electrons.........
what's the (snowy sour) mixture?
CH6COOH
Vinegar pickles
6. The valence number of a metallic element x is 3. What is the chemical formula of its B. Nitride?
A plant uses the energy from sunlight to create oxygen and glucose from carbon dioxide and water which statement is true about the changes that have occurred
Answer:
The correct answer choice is A. A chemical change has occurred because new compounds have been produced.
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.Example: Melting of ice A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.Example: photosynthesis
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
Thus the true statement is a chemical change has occurred because new compounds have been produced.
Differentiate between acids and bases on the basis of their pH values Give an example of each type. Please help worth 100 points!!!!!!!
Answer: Well 0-7 is acid, and 0-3 is a strong acid. 4-7 is a weak acid. 8-11 is strong base. 12-14 is weak base!
Explanation:
What is the molecular geometry if you have a double bond, a single bond and 1 lone pair around the central atom?
Answer:
4 pairs are needed for the bonds, leaving 1 lone pair. Each double bond uses 2 bond pairs and can be thought of as a single unit. There are 2 double bond units and 1 lone pair, which will try to get as far apart as possible - taking up a trigonal planar arrangement.
what happens if we mix vitamin c and d together
we can get rid of scurvy as well as rickets ......
How are oxidation-reduction reactions related to how you use energy?
Answer:
In oxidation reduction reactions, one species gets reduced by taking on electron(s) and another species gets oxidized by losing electrons. They also flow by a wire
Explanation:
calculate the mass of 1 molecule of water and 100 molecules of glucose
Answer:
The mass of 1 molecule of water is 18.02
The mass of 100 molecules of glucose is 18000
I hope this is correct, and helps you out :)
Which functional group is within the compound shown below?
what is the name of the compound N2O5
Answer:
Dinitrogen pentoxide also known as Nitrogen pentoxide or nitric anhydride (these are all the same thing just different names people call them)
Which one of the following statements about balanced is true? A reaction is balanced by
A compound has the following percentage composition: 40.0% carbon, 6.72% hydrogen, 53.28% oxygen. What is the amount of carbon moles in 200g of the compound?
Answer:
So we're trying to find the number of carbon moles in the compound. We know that we have 200g of the compound and that 40% of it is Carbon. and 40% of 200 is 80g (change 40% into a decimal and multiply it by 200 and you get 80g)
So 80g of the compound is carbon. In order to find the moles of Carbon, I have to divide the mass by the molar mass of the element.
We know from our periodic table that the molar mass for carbon is 12g/mol
[tex]\frac{80}{12} = 6.67\ mol[/tex]
Therefore we have 6.67 moles of carbon in the compound
Answer:
6.67 moles of carbon in compound
Sort the sentences based on whether they describe the properties of a heterogeneous or a homogenous mixture.
Answer:
Carbonate Sodium Hydrogen
using the formula F=ma, what force is required to accelerate a car weighing 642 kg at 13 m/s2
REALLY NEED HELP RN
HELP ME ?
PLEASE!??
Answer:
8,346 kmxm/s2
Explanation:
this is physics not chem but you just multiply 13 by 642 to get 8,346. also I'm sorry but it's easy
What is the process of solar nuclear fusion?
Answer:
base sa research po
Explanation:
In the core of the Sun hydrogen is being converted into helium. This is called nuclear fusion. It takes four hydrogen atoms to fuse into each helium atom. During the process some of the mass is converted into energy.
Answer:
Hydrogen atoms are fused into deuterium, then helium-3, then helium-4, each step giving off large amounts of energy.
Explanation:
Because that's how it works :D
Which branch of Earth science focuses more specifically on Earth's atmosphere?
Answer:
Meteorology
Explanation:
Meteorology focuses on Earth's atmosphere and, especially, how changes in the atmosphere affect weather and climate on Earth's surface.
What is the job of cellular respiration?
Answer:
to break down sugar in the presence of oxygen to release energy in the form of ATP
Explanation: i just finished this chapter of the class
which change of phase is exothermic
Write a paragraph on "lipids as pigments".
The balanced chemical equation for the conversion of nitrogen to ammonia is:2N₂(g) + 3H2(g)2NH3(g): Which of the following statements concerning this chemical equation is/are correct?
1. In a 22.4 L container at standard temperature, 2 atm of nitrogen gas will react with 3 atm of hydrogen gas to produce 2 atm of ammonia gas.
2. At standard pressure and temperature, 22.4 L of nitrogen gas will react with 22.4 L of hydrogen gas to produce 22.4 L of ammonia gas.
3. At standard pressure and temperature, 44.8 L of nitrogen gas will react with 67.2 L of hydrogen gas produce
22,4 L of ammonia gas
Answer:
At standard temperature and pressure, 44.8
Explanation: