Subatomic Particles
Missing Values
Special Atoms
Valence Electrons
Symbols
100

This subatomic particle has a positive charge and is found in the nucleus.

Protons

100

The atomic number of an atom is 8, and its mass number is 16. How many neutrons does it have?

8

100

This is the term for atoms of the same element with different numbers of neutrons.

Isotopes

100

These electrons are found in the outermost shell of an atom.

Valence Electrons

100

The letter "O" is the chemical symbol for this element.

Oxygen

200

This particle has no charge and helps hold the nucleus together

Neutrons

200

An atom has 17 protons, 18 electrons, and 20 neutrons. What is its overall charge?

-1

200

This is the term for an atom with a charge due to gaining or losing electrons.

Ions

200

Oxygen has this many valence electrons.

6

200

The number above an element's symbol in the periodic table represents this. 

Atomic Number

300

This negatively charged particle orbits the nucleus

Electrons

300

An atom has a mass number of 23 and 11 protons. How many neutrons does it have?

12

300

Carbon-14 and Carbon-12 are examples of these.

Isotopes

300

Atoms in Group 1 of the periodic table have this many valence electrons.

1

300

The number below an element's symbol on the periodic table is its average ____.

Atomic Mass

400

The number of these particles determines the element's atomic number.

Protons

400

If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its mass number?

12

400

A chlorine atom with 17 protons and 18 electrons has this charge.

-1

400

Elements in this group have a full outer shell of valence electrons.

Group 8
Nobel Gasses

400

In the isotope Carbon-14, the number 14 represents this.

Mass Number

500

These two particles contribute to an atom's mass.

Protons and Neutrons

500

An ion has 19 protons and 18 electrons. What is the ion’s charge?

+1

500

Isotopes of an element differ in this property.

Neutrons

500

Fluorine has 7 valence electrons. It needs this many more to have a full outer shell.

1

500

The isotope notation for an oxygen atom with 8 protons and 10 neutrons is written as this.

18 over 8, O

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