The average atomic mass of Rubidium : 85.556 u
Further explanationIsotopes are atoms that have the same atomic number but different mass numbers
Each isotope has an abundance which is usually expressed as a percentage
The average relative mass of atoms is obtained by adding the product of the percentage and mass of each isotope
Can be formulated:
[tex]\tt Average~Mass~atom~X=mass~isotope~ 1\times \%1+mass~isotope~2\times \%2+..[/tex]
The abundance of 85 Rb is 72.2% and the abundance of 87 Rb is 27.8%, so
mass isotope 1=85, %abundance=72.2
mass isotope 2=87, %abundance=27.8
The averages atomic mass of Rubidium :
[tex]\tt average~atomic~mass=85\times 0.722+87\times 0.278\\\\average~atomic~mass=61.37+24.186\\\\average~atomic~mass=\boxed{\bold{85.556~u}}[/tex]
HELPP ANSWERSSS!!!!
A student designs an investigation to test the reactivity of two elements with HCl to produce hydrogen gas. Using the periodic table as a model which of the following would you expect to produce the most hydrogen gas within the first minute of the reaction?
A.
Al, because it has the higher ionization energy and more readily accepts electrons to participate in a reaction.
B.
Al, because it has the lower ionization energy and more readily gives up valence electrons to participate in a reaction.
C.
Cs, because it has the lower ionization energy and more easily gives up its valence electrons to participate in a reaction.
D.
Cs, because it has the higher ionization energy and more easily gives up its valence electrons to participate in a reaction.
Answer:
C. Cs, because it has the lower ionization energy and more easily gives up its valence electrons to participate in a reaction.
Explanation:
The Cs will produce the most hydrogen gas because it has a lower ionization energy and more easily gives up its valence electrons to participate in the reaction.
Ionization energy is the energy required to remove the most loosely held electrons in an atom. Atoms with lower ionization energy readily goes into reactions. This is because they will present little barrier for the reaction to occur.Write the balanced Ka and Kb reactions for HSO3- in water. Be sure to include the physical states of each species involved in the reaction.Ka:_________Kb:_________NOTE: Use the chemical equation editor tool to input the physical states. Do not subscript the physical states of the compounds.
Answer:
Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]
Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]
Explanation:
An amphoteric substance as HSO₃⁻ is a substance that act as either an acid or a base. When acid:
HSO₃⁻(aq) + H₂O(l) ⇄ H₃O⁺(aq) + SO₃²⁻(aq)
And Ka, the acid dissociation constant is:
Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]When base:
HSO₃⁻(aq) + H₂O(l) ⇄ OH⁻(aq) + H₂SO₃(aq)
And kb, base dissociation constant is:
Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]What is the mole ratio of oxygen to butane?
Answer:
13:2
With the number of moles of butane equal to 54 grams, it is possible to find the moles of O2 that can react with it. Taking coefficients from the reaction equation (13 O2 and 2 C4H10), the molar ratio of O2 to C4H10 is 13:2.
Explanation:
HELP Which type of light is stored energy?
A. Kinetic
B. Potential
C. Thermal
D. Field
Answer:
B
Explanation:
Answer:
Potential
Explanation:
An atom of an element can be identified from its
A. atomic mass
B. number of neutrons
C. Total change
D. Number of protons
Answer:
D. number of protons
Explanation:
Sana makatulong
Given the composition of your food, which of the following is good for your health? WHICH OF THEM IS BAD?
Answer:Eating the right foods can help your body cope more successfully with an ongoing illness. ... corn syrup) are also bad for long-term health, especially in people with diabetes. ... Also, you may have nutritional deficiencies due to certain health or life conditions, such ... Eating a balanced diet can help prevent these conditions.
Explanation:
draw a well-labelled diagram showing how your body digests food
i too used it
i thought it will help
nice time. .....
Explanation:
...................
What is the number of
nitrogen atoms in 12.0 g of
CO(NH2)?
[Avogadro constant = 6.02
x 1023 moll; Molar mass of
CO(NH2) = 60 g mol']
Answer:
1.2 x 10²³atoms
Explanation:
Given parameters:
Mass of CO(NH₂) = 12g
Unknown:
Number of Nitrogen atoms = ?
Solution:
Given compound;
CO(NH₂);
In;
1 mole of CO(NH₂), we have 1 mole of N
let us find the number of moles of CO(NH₂);
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Number of moles = [tex]\frac{12}{60}[/tex] = 0.2moles
Since
1 mole of CO(NH₂), we have 1 mole of N
0.2 mole of CO(NH₂) will have 0.2mole of N
1 mole of a substance contains 6.02 x 10²³ atoms
0.2 mole of N will contain 0.2 x 6.02 x 10²³ atoms = 1.2 x 10²³atoms
What are the products in a chemical reaction?
A. The substances that result from a chemical reaction
B. The substances that do not take part in a reaction
c. The substances that cause the reaction to occur
thing
D. The substances that react in a chemical reaction
Answer:
A
Explanation:
The product is the result of the chemical reaction hope that helped
Suppose that the microwave radiation has a wavelength of 12.4 cm . How many photons are required to heat 255 mL of coffee from 25.0 ∘C to 62.0 ∘C
Answer:
Explanation:
wavelength λ = 12.4 x 10⁻² m .
energy of one photon = h c / λ
= 6.6 x 10⁻³⁴ x 3 x 10⁸ / 12.4 x 10⁻²
= 1.6 x 10⁻²⁴ J .
Let density of coffee be equal to density of water .
mass of coffee = 255 x 1 = 255 g
heat required to heat up coffee = mass x specific heat x rise in temp
= 255 x 4.18 x ( 62-25 )
= 39438.3 J .
No of photons required = heat energy required / energy of one photon
= 39438.3 / 1.6 x 10⁻²⁴
= 24649 x 10²⁴
= 24.65 x 10²⁷ .
Match the molecules to the correct state of matter
Answer:
1. solid, 2.liquid, 3.gas.
Answer:
1 b. solid
2 a. liquid
3 c. gas
What is the volume of 139.05 g of neon gas at STP?
Ans:___L Ne
Given :
Mass of neon gas at STP.
To Find :
The volume of 139.05 g of neon gas at STP.
Solution :
Molar mass of neon, M = 20 g.
Number of moles in 139.05 g of neon :
n = 139.05/20 ≈ 7 moles
We know, volume of 1 mole of any atom/molecules in STP is 22.4 L of volume.
So, volume of 7 moles of neon is :
V = 7×22.4 L
V = 156.8 L
Therefore, volume of 139.05 g of neon gas at STP is 156.8 L.
1.50 x 10^23 atoms Mg
Suppose you have 250.0 mL of a 0.350 M sodium hydroxide solution. How many moles of sodium hydroxide are in the solution?
Explanation:
number of moles can be derived from molarity law as shown in the figure
The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.
Calculation of the number of moles:
Since there is 50.0 mL of a 0.350 M sodium hydroxide solution.
So here the no of moles should be
[tex]= Molarity * volume\\\\= 250 *10^-3 * 0.350[/tex]
= 0.0875 moles
hence, The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.
Learn more about moles here: https://brainly.com/question/8759992
Which functional group will cause a compound to have a boiling point greater than that predicted only by molar mass?
-Alkene
-alkane
-ketone
-ether
-alcohol
Answer: Alcohol
Explanation:
What is the independent variable and the dependent variable?
Answer: A variable that is intentionally changed during an experiment
Explanation:Hope it works
Explain the difference in reactivity between CH3+OH2 and CH3OH in a nucleophilic substitution reaction.
Here ya go, hope this helps! :)
how is the atmosphere characterized
Elements on the current periodic table are organized by what?
atomic number
number of neutron
reactivity
can you help me plz..?!!
Answer:you killed a person
Explanation:that is a example
I looked around just put these into your own words :)
Explanation:
One common method of separation is filtration. Filters are used everywhere. We use them in our houses to filter dust and mites out of the air we breathe. We use them to filter impurities from our water.
It is important to be able to separate mixtures to obtain a desired component from the mixture and to be able to better understand how each component works.
In chemistry and chemical engineering, a separation process is commonly used to transform a mixture of substances into two or more distinct materials. The separated products might differ in chemical properties or some physical property, such as size or crystal modification or other separation into different components.
Hopefully this helps you out.
What will the pressure of the gas be if the temperature rises to 87°C?
A. 60 kPa
B. 161 kPa
C. 16 kPa
D. 41 kPa
Answer:
A. 60 kPa
Explanation:
P2 = p1 times t2 / t1
Which type of energy would digesting
food be?
A. Feild
B.solar
C. Thermal
D. kinetic
E. Tube
F. chemical
Answer:
F . chemical
Explanation:
Answer:
f
Explanation:
The maximum allowable concentration
of lead in drinking water is 9.0 ppb. If 2.0
X 10 grams of lead is present in 250
mL of water, is it safe to drink the water?
Support your answer with mathematical
proof.
We are given:
Maximum concentration of Lead in water = 9 ppb
Mass of Lead in the given solution = 20 grams
Volume of water in the given solution = 250 mL
What is 1 ppb?
1 ppb, short for parts-per-billion. As from its name itself, ppb is used to find how many molecules of solute are present per 1 Billion molecules of the solvent
you can also use it in grams to get the formula:
1 ppb = 1 gram of solute / 1 Billion grams of Solvent
Finding the Ideal ppb concentration:
We are given that the maximum allowed concentration is 9 ppb
which means that we need 9 grams of the solute per 1 Billion grams of Solvent: 9 grams of Solute / 10⁹ grams of Solvent
ppb Concentration of the given solution:
We have 20 grams of Solute in 250 mL of water
Since the density of water is 1 gram/mL
20 grams of Solute / 250 grams of Solvent
As we can see, this fraction is FAR more large that the maximum ppb concentration
This means that the concentration of Lead in the Given solution is higher than the maximum amount and Hence, is unfit to drink
In an enviroment in which the pH is 7, a carboxylic acid will exist as:
A) a negatively charged species
B)a positvely charged species
C)a neutral species
D)none of the other answers are correct
Answer:
The correct answer is C.
Explanation
The pH scale ranges from 0-14 so 7 is neutral.
During electrolysis, where do reduction reactions occur?
Answer:
at the negative cathode
Explanation:
Reduction happens at the negative cathode because this is where positive ions gain electrons. Oxidation happens at the positive anode because this is where negative ions lose electrons.
Answer:
B. in the cathode of an electrolytic cell
Explanation:
plz help it's due in 5 min
Answer:
what is the question then we can help you out
Answer:
51.84
Explanation:
what are bonds in which valence electrons are shared
Answer:true
Explanation:
Covalent bonds are a class of chemical bonds where valence electrons are shared between two atoms, typically two nonmetals. The formation of a covalent bond allows the nonmetals to obey the octet rule and thus become more stable.
Answer:
covalent bonds are bonds in which valence electrons are shared.
Explanation:
of rational function
1
3. + 3 < 0
3x-1
nctions.
Answer:
I didn't understand questions properly. Sorry
Which TWO statements describe the ocean floor giving brainliest plz help and explain
Answer:
A.There are many active undersea volcanoes
B.There are long underwater mountain chains
True or False: A buffer solution containing equimolar amounts of the base, aniline, and the salt of its conjugate acid, aniline hydrochloride, will result in an acidic buffer solution. (aniline: Kb = 4.3x10-10)?
Answer:
It is TRUE!
Explanation:
Answer:
True is your answer
Explanation: