An atomic mass unit is defined as a mass equal to one twelfth the mass of an atom of carbon-12. The mass of any isotope of any element is expressed in relation to the carbon-12 standard. For example, one atom of helium-4 has a mass of 4.0026 amu. An atom of sulfur-32 has a mass of 31.972 amu.
Answer:
The answer is A. Polar covalent; negatively
Explanation:
Hydrogen bonds form between molecules containing polar covalent bond the hydrogen bond is been a hydrogen atom of one molecule and a partially negative charged atom of another.
Example 
(water):- It contain a slight positive charge on one side and a slight negative charge on the other.
The number of atoms of each element :
C : 1 atom
H : 3 atoms
Br = 1 atom
<h3>Further explanation</h3>
Given
Bromomethane-CH₃Br
Required
The number of atoms
Solution
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
The number of atoms in a compound is generally indicated as a subscript after the atom
C : 1 atom
H : 3 atoms
Br = 1 atom
Total 5 atoms
