Question

mass number equals
the number of
________ + ________

30
zich
zinc
65.39
atomic # = 30
mass number = __________

of protons = 30

of neutrons = 35

of electrons = 30

3
li
lithium
6.941
atomic # = 3
mass number = __________

of protons = 3

of neutrons = 4

of electrons = 3

Explanation:

Step1: Recall mass number formula

The mass number of an atom is defined as the sum of the number of protons and neutrons in its nucleus:
$$\text{Mass number} = \text{Number of Protons} + \text{Number of Neutrons}$$

Step2: Calculate Zinc's mass number

For Zinc, number of protons = 30, number of neutrons = 35. Substitute values:
$$\text{Mass number (Zinc)} = 30 + 35 = 65$$

Step3: Calculate Lithium's mass number

For Lithium, number of protons = 3, number of neutrons = 4. Substitute values:
$$\text{Mass number (Lithium)} = 3 + 4 = 7$$

Step4: Fill top formula blanks

The mass number equals protons plus neutrons.

Answer:

Top blanks (left to right): Protons, Neutrons
Zinc: Mass number = 65
Lithium: Mass number = 7