Elements

Question 1

What is the number at the end of an isotope’s name?

Revolt · Accepted Answer

mass number

Question 2

All atoms of the element potassium have 19 protons. One of the most stable types of potassium atoms has the mass number 39.

Revolt · Accepted Answer

20

Question 3

The model below shows a calcium atom.

Revolt · Accepted Answer

8

Question 4

The simple model below is a neutral magnesium (Mg) atom with the element’s most common mass number.

Revolt · Accepted Answer

It must lose two electrons and become an ion.

Question 5

What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron?

Revolt · Accepted Answer

energy

Question 6

One isotope of sodium has 11 protons and 7 neutrons. What is the mass number of this isotope?

Revolt · Accepted Answer

18

Elements Answers