The Structure of Matter - Molecules

The Structure of Matter - Molecules

7th Grade Life Science

May 23^rd, 2023

Labelling

Label the atomic symbol, atomic number, and name of nitrogen in the picture.

Drag labels to their correct position on the image

Element Name

Atomic Number

Atomic Symbol

Multiple Choice

An atom has an atomic number of 23 and a mass number of 50. How many protons are in the nucleus of this atom?

• 23

• 27

• 50

Multiple Choice

An atom has an atomic number of 23 and a mass number of 50. How many neutrons are in the nucleus of this atom?

• 23

• 27

• 50

• Neutrons keep the protons from flying away from each other

• They make the nucleus more stable

• Every element has a proton:neutron ratio that is the most stable

Neutrons

• Atoms can bind together to form molecules

• The electrons make that possible by either:

  • Moving from one atom to another

  • Being shared between atoms

Electrons

• An ion is an atom that has either a positive or negative charge

• It has to either gain, or lose, electrons

Ions

Multiple Choice

Quick review! Electrons are:

• Positive!

• Neutral!

• Negative!

Multiple Choice

If an atom has the same number of protons and electrons, it is:

• Positive.

• Neutral.

• Negative.

Multiple Choice

If a neutral atom loses an electron, it would become:

• Positive.

• Neutral.

• Negative.

Multiple Choice

If a neutral atom gains an electron, it would become:

• Positive.

• Neutral.

• Negative.

Open Ended

Why do you think an atom becomes an ion by gaining/losing electrons, instead of gaining/losing protons?

An atom becomes:

• a Cation if it loses electrons (and becomes positive)

• an Anion if it gains electrons (and becomes negative)

Cations and Anions

• When an electron transfers (or moves) from one atom to another, two ions form

  • One is positive and the other is negative

• They become attracted to each other and form an ionic bond

Ionic Bonds

• In a covalent bond, the electrons are shared between two atoms

• They don't move from one atom to another

• The shared electrons hold the two atoms together

Covalent Bonds

Multiple Choice

A cation (or positive ion) is formed when an atom:

• Loses electrons.

• Gains electrons.

Multiple Choice

An anion (or negative ion) is formed when an atom:

• Gains electrons.

• Loses electrons.

Multiple Choice

_______________ bonds are formed when electrons are shared between atoms.

• Ionic

• Covalent

Multiple Choice

_______________ bonds are formed when electrons are transferred from one atom to another.

• Ionic

• Covalent