Elements

Question 1

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 2

The model below shows a calcium atom.

Revolt · Accepted Answer

8

Question 3

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 4

If we have a sample of silicon (Si) atoms that has 14 protons, 14 electrons, and 18 neutrons

Revolt · Accepted Answer

silicon-32

Question 5

The chemical symbol for the element calcium is Ca. What would be the symbol representing calcium atoms that have lost two electrons?

Revolt · Accepted Answer

Ca+2

Question 6

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

Revolt · Accepted Answer

mass number

Question 7

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

Revolt · Accepted Answer

18

Question 8

One way in which elements differ from each other is the structure of the electron cloud in each element’s atoms. In an electron cloud, an electron that is farther away from the nucleus has

Revolt · Accepted Answer

a higher energy than an electron near the nucleus.

Question 9

Which are different forms of an element that have different numbers of neutrons?

Revolt · Accepted Answer

isotopes

Question 10

A potassium atom (atomic number 19) loses an electron while forming a bond with another atom.

Revolt · Accepted Answer

It is a positive ion that has one less valence electron than a neutral potassium atom.

Elements Answers

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