Answer:
35.48 uma
Explanation:
An isotope is when an element has equal numbers of protons but different mass value because it has different amount of neutrons.
To calculate the average atomic mass with the given data:
First change de percentages to fractional numbers, divide by 100.
Remember the sum of a percentage is equal to 100, but when you are adding the fractions the sum is equal to 1.
76/100 = 0.76
24/100 = 0.24
% fraction
76.00 0.76
24.00 0.24
total100.00 1.00
Now, multiply the mass with their corresponding fraction:
35(0.76) = 26.60
37(0.24) = 8.88
% fraction amu amu
76.00 0.76 35 26.60
24.00 0.24 37 8.88
total100.00 1.00 average 35.48
Now you add the calculated mass to obtain the average atomic mass of the element.
And the value you will get is 35.48 amu.
I included an excel table so you can review it, I like to organize all the given data and the calculation in tables, also I think is easier to understand.
Answer:
C, physical change
Explanation:
take a look at the equation. Next to each form of water do you see the little (g) and (l)? These represent the state of matter the water is in. So, the water is going from a gas to a liquid. The chemical compound is the same so its a physical change, not chemical, and it is reversible. You could change the liquid water back to the gas through evaporation. Endothermic has literally nothing to do with this equation so you can easily eliminate that answer choice.
Answer:
Sodium fluoride is a colorless crystalline solid or white powder, or the solid dissolved in a liquid. It is soluble in water. It is noncombustible.(I got this answer from g o o g l e)
Explanation:
Particles are smaller, a reactant would be exposed to more cobalt atoms. Causing the reaction to happen quicker than with larger particles.
