Answer:
The percent natural abundance is 27.95% for the heavier isotope (86.901 amu)
Explanation:
The atomic mass of Rubidium (Rb) is 85.468.
To find the percent natural abundance, first we need to use the following equation:
84.912x + 86.901(1-x) = 85.468
x represents the percent natural abundance, in basic decimal form
In order to find x, we will use the distributive property, combine like terms and then move the constant to the other side to get x.
We are first finding the percent natural abundance of the first isotope to make this easier for us.
84.912x + 86.901(1-x) = 85.468
-> 84.912x + 86.901- 86.901x = 85.468
-> 86.901 - 1.989x = 85.458 (like terms were combined)
-> Subtract both sides by 86.901
-> Divide both sides by-1.989x
x = 0.720462544
Now turn this into a percent by multiplying by 100.
--> 72.05% for the first isotope (the one that contains 84.912 amu)
To find the natural abundance of the other isotope (the denser, heavier isotope), you could just subtract 72.05 from 100 to save time, but the usually desired way (the way that your teacher would probably want you to do) is down below:
We plug this decimal for the x-value into the parentheses from earlier:
(1 -x) ---> ( 1 - 0.720462544 ) = 0.279537456
Now we just need to convert this to a percent by multiplying by 100
0.279537456 * 100 = 27.95% of the heavier isotope (86.901 amu)
A syringe with 32.0 mL contains gas at 649.0 mmHg. The plunger is pushed in and now the volume is 19.5 mL. What is the new pressure?
Answer:
1.40 atm
Explanation:
P1V1 = P2V2
P2= P1* V1/V2
P1=649.0mmHg
V1= 32.0mL
V2= 19.5mL
P2=649.0mmHg*32.0ml/19.5ml=
1065.03mmHg
To get mmHg to atm. The formula is 1atm/760mmHg
Use the answer you got in mmHg to convert into (atm), If you were asked
1065.03mmHg*(1atm/760mmHg)= 1.40atm
Compared to compounds with network structures, compounds arranged in molecules (covalent bonds) have ____________ melting points.
Explanation:
.... have lower melting points.
99% 1H
0.8% 2H
0.2% 3H
Average Atomic Mass = [answer] amu
PLEASE HELP ME
Answer: 1.01 atomic mass units or amu
Explanation:
What is Newton's First Law known as? The Law of
____
Answer:
inertia
Explanation:
Answer:
Law of inertia, also called Newton's first law, postulate in physics that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
Explanation:
hope it helps, please mark brainliest
look.............................................
Answer:
Your answer is correct.
Explanation:
The steel paper clip would only move because it has steel in it, which is a magnetized material, plastic on the other side, is made up of polymers which are not attracted to the magnetic force, causing it not to move.
Question 11 of 32
When do scientists form a hypothesis?
A. Before they form a theory
B. After they form a theory
O C. Before they perform an experiment
D. After they perform an experiment
SUBMIT
Answer:
C
Explanation:
a hypothesis always comes first
Answer:
C
Explanation:
They form hypothesis first, then perform the experiment to test the hypothesis. After multiple experiments, they form a theory.
Thus C is correct
please give thanks by hitting that heart button :)
Pb(SO4)2 + 4 LiNO3 → Pb(NO3)4 + 2 Li2SO4
If 2.25 moles of lead (II) sulfate are combined with 9.62 moles of lithium nitrate, how moles of lithium sulfate can be created? please help
Answer:
4.5 moles of lithium sulfate are produced.
Explanation:
Given data:
Number of moles of lead sulfate = 2.25 mol
Number of moles of lithium nitrate = 9.62 mol
Number of moles of lithium sulfate = ?
Solution:
Chemical equation:
Pb(SO₄)₂ + 4LiNO₃ → Pb(NO₃)₄ + 2Li₂SO₄
Now we will compare the moles of lithium sulfate with lead sulfate and lithium nitrate.
Pb(SO₄)₂ : Li₂SO₄
1 : 2
2.25 : 2/1×2.25 = 4.5 mol
LiNO₃ : Li₂SO₄
4 : 2
9.62 : 2/4×9.62 = 4.81 mol
Pb(SO₄)₂ produces less number of moles of Li₂SO₄ thus it will act as limiting reactant and limit the yield of Li₂SO₄.
Please answer on paper and send a picture of the answer. thank you
Answer:
I dont know how to take a picture so I will just tell you the answer. The answer is no.
Explanation:
Hope this helps. :) :D
What is an example of a congenital disorder
Answer:
down syndrome
Explanation:
If an object has a velocity of 8 m/s and
a momentum of 40 kg.m/s, what is the
mass of the object
Answer:
Explanation:
The Kinetic Energy (K.E) of an object can be calculated as:
We are given:
K.E = 480 K
Velocity of the object = v = 8 m/s
Using the values, we get:
Thus, the mass of the object will be 15 kg.
The mass of the object at the given momentum and speed is determined as 5 kg.
Momentum of the object
The momentum of the object is calculated as follows;
P = mv
where;
m is mass of the objectv is speed of the objectm = P/v
m = 40/8
m = 5 kg
Thus, the mass of the object at the given momentum and speed is determined as 5 kg.
Learn more about momentum here: https://brainly.com/question/7538238
#SPJ2
find the pOH of a solution made by dissolving 10.4g of HCl in a 500mL solution of water
The pOH of a solution : 13.756
Further explanationMass HCl=10.4 g
mol HCl (MW=36.5 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}=\dfrac{10.4}{36.5}=0.285[/tex]
Volume of HCl = 500 ml = 0.5 L
[tex]\tt M=\dfrac{n}{V}\\\\M=\dfrac{0.285}{0.5}=0.57~M[/tex]
HCl ⇒ H⁺ + Cl⁻
[H⁺]=[HCl]=0.57 M
pH= - log[H⁺]
pH=-log[0.57]=0.244
pH+pOH=14
pOH=14-0.244
pOH=13.756
What is the volume of 2 moles of He at STP?
Answer:
STP conditions imply a temperature of 273.15 K and a pressure of 100 kPa. When tose conditions are met, 1 mole of any ideal gas will have a volume of 22.7 L. So, if 1 mole occupies a volume of 22.7 L, 2 moles will occupy a volume twice as big. Likewise, 0.5 moles will occupy half the volume 1 mole occupies. Assuming that the gas is at standard temperature and pressure (STP), one mole of any gas occupies 22.4 L . This means the number of moles of O2 is 222.4=0.089 mol .
Explanation:
10 points Which of these is the best example of heat transfer by radiation? *
1 point
a) A satellite is warmed by sunlight.
b) A ceiling fan cools a warm room.
c) Butter melts on warm bread.
d) Puddles of water cool a warm tile floor.
Answer:
a) A satellite is warmed by sunlight.
Explanation:
Heat transfer by radiation mostly involves heat gain or heat loss from the Sun. In this case, Option A is the only option where sunlight is involved so it is the best example of heat transfer by radiation.
Which of the following correctly describes a proton? Group of answer choices Location: nucleus, contribution to mass: usually about half, charge: positive Location: nucleus, contribution to mass: virtually none, charge: positive Location: outside nucleus, contribution to mass: usually about half, charge: positive Location: nucleus, contribution to mass: usually about half, charge: none
Answer:
Location: nucleus, contribution to mass: usually about half, charge: positive
Explanation:
Protons are a part of the nuclear particles alongside the neutrons. Protons and neutrons are all together called sub-atomic particles and they share the nucleus at the center of an atom together.
Protons carry positive charges. They determine the mass of the atom alongside the neutrons. They contribute half to the mass of an atom and the other part is lies on the mass of a neutron. Neutrons do not carry any charges.Which of the following steps will slow down the reaction between coal and oxygen?
Answer:
decrease temperature of the oxygen
Explanation:
Answer: I believe it it decrease temp of oxygen
Explanation:
Which of the following students best describes an element?
Answer:
I dont see anything.
Explanation:
But an element is a substance that is made only out of one atom.
the diagrams represent the same number of particles of a gas in 2 containers D snd E, Which have different volume. the two containers are at the same temperature.
in which container will the pressure be higher ?explain your answer
In container E, the pressure will be higher than container D
Further explanationGiven
Container with :
the same particlesthe same temperaturethe different volumeRequired
The higher pressure container
SolutionBoyle's Law stated that :
At a constant temperature, the gas volume is inversely proportional to the pressure applied
[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
From the diagram (picture), it shows that the volume of container D is greater than container E, so the pressure applied to container D will be less than the pressure applied to container E
Convert 12.5 km/L to mi/gal.
Answer:
29.40182
Explanation:
What is a transform boundary, and how does it affect the land?
Answer:
simple
Explanation:
A transform fault or transform boundary is a fault along a plate boundary where the motion is predominantly horizontal.[1] It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone.[2]
(2k-1)²
what the answer pls.
Answer:
4k^2-4k+1
Explanation:
Plx give brainlyest
What happens to the velocity of an object when balanced forces act on it?
a.
There will be no change
c.
There will be negative acceleration
b.
There will be positive acceleration
d.
Velocity will change, but not acceleration
Answer:
There will be negative acceleration.
Explanation:
I majored in Physics
Answer:
A. There will be no change
Explanation:
Velocity is defined as the directional speed of an object in motion. Balanced forces do not result in any change in motion. Thus, there would be no change in velocity.
Please answer fast, shouldn't take long to do ^-^ (will give brainliest)
Which is the correct formula for iron (II) phosphate?
a. Fe2PO4
b. Fe3(PO4)2
c. Fe2PO3
d. Fe(PO4)2
e. Fe(PO3)2
Answer:
B
Explanation:
What energy transformation occurs when a person is running
Answer:
Kinetic Energy (Hope This Helps)
Explanation:
(Brainliest)
Answer:
Chemical energy to kinetic energy. (Arguably heat energy (thermal) because of respiration)
what are two ways that substances can pass through a cell membrane out of the cell
Answer:
Passive transport, and Active transport
Explanation:
Do u need an explanation?
If so you can tell me and I'll edit it
Hope this helped a little!
The element in group 4 and period 3
materials that prevent the heat to flow call
Answer:
Materials that prevent heat to flow are known as heat insulators.
Explanation:
hope it helps! ฅ'ω'ฅ
In a covalent compound like O2, two pairs of electrons are shared between the atoms. What is the name given to a bond like this?
Explanation:
The bond is a covalent bond.
2. How many moles are found in 3.2 x 1023 atoms of NaCl?
Answer:
0.53 mol NaCl
General Formulas and Concepts:
Chemistry - Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
3.2 × 10²³ atoms NaCl
Step 2: Identify Conversions
Avogadro's number
Step 3: Convert
[tex]3.2 \cdot 10^{23} \ atoms \ NaCl(\frac{1 \ mol \ NaCl}{6.022 \cdot 10^{23} \ atoms \ NaCl} )[/tex] = 0.531385 mol NaCl
Step 4: Check
We are given 2 sig figs. Follow sig fig rules and round.
0.531385 mol NaCl ≈ 0.53 mol NaCl
Write the name of the covalent compound ON.
Answer:
the answer is oxygen mononitride
A student mixes two chemicals in a test tube. She notices that the mixture starts to bubble and the test
tube feels very warm. The student most likely concludes that the mixture is-
F. a chemical reaction that happened too quickly.
G. an endothermic reaction that absorbed thermal energy.
H. an exothermic reaction that released thermal energy.
J. not a chemical reaction.
Answer:
H. an exothermic reaction that released thermal energy.
Explanation:
The student will most conclude that this is a chemical reaction in which thermal energy is released to the environment.
Such reactions accompanied by the release of thermal energy are exothermic reactions.
In an exothermic change, heat is liberated to the surrounding. The surrounding becomes hotter at the end of the changes. For such reaction we say that enthalpy change is negative.For endothermic reactions, heat is absorbed. At the end of the reaction, the system is cold.
