Which statement accurately compares the trends in atomic number and atomic mass in the periodic table?

a. the atomic number increases from left to right, while the atomic mass increases from right to left.
b. the atomic mass increases from left to right, while the atomic number increases from right to left.
c. both the atomic mass and the atomic number increase from left to right.
d. both the atomic mass and the atomic number increase from right to left.

C.Both the atomic mass and the atomic number increase from left to right.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer