True or false, The atomic number of an element is a whole number that decreases as you read across each row of the periodic table from left to right.

Read the given expression. x = number of protons − number of core electrons which of the following explains the identity of x and its trends across a period? x is the effective nuclear charge, and it remains constant across a period. x is the screening constant, and it remains constant across a period. x is the effective nuclear charge, and it increases across a period. x is the screening constant, and it increases across a period.

Evaluate this exponential expression,8. (2 + 3)2 – 42

What is the number of moles in 15.0 g ash3?