B. protons; neutrons
C. neutrons; electrons
Answer: Option (B) is the correct answer.
Explanation:
Atomic mass is defined as the summation of total number of protons and neutrons present in an element.
On the other hand, atomic number means the total number of protons present in an element.
For example, atomic number of sodium is 11 and number of neutrons present in it are 12.
Hence, atomic mass of sodium = no. of protons + no. of neutrons
= (11 + 12) amu
= 23 amu
Therefore, we can conclude that the atomic mass of an element can be approximated by adding the number of protons plus the average number of neutrons.
What is the molecular formula of the alcohol?
Answer:
Explanation:
For a compound as:
Let say your sample weighs 100 g, then you have
52 g of C
35 g of O
13 g of H
Now you need to calculate the moles in the sample:
moles of C = 52 / 12 = 4.3333
moles of O = 35 / 16 = 2.1875
moles of H = 13 / 1 = 13
Now you divide the moles by the least to have a proportion (2.1875):
moles of C = 4.3333 / 2.1875 = 2
moles of O = 2.1875 / 2.1875 = 1
moles of H = 13 / 2.1875 = 6
So the molecule proportion of atoms is C:H:O = 2:6:1
Now to find x you have to calculate the MM:
MM = 12 * 2x + 1 * 6x + 16 * x = 46x
For x = 1 => MM = 46(1) = 46
For x = 2 => MM = 46(2) = 92
Since the MM is between 30 and 80, x = 1