Chemistry

When is an ionic bond formed?

• when electrons are shared

• when protons are shared

• when ions of opposite electrical charges attract each other

• when a positive hydrogen attracts a negative atom in another molecule

Which two subatomic particles are found in the nucleus of an atom?

• Neutrons and Protons

• Shells and Electrons

• Electrons and Protons

• Electrons and Neutrons

An atom becomes a positive ion when it

• gains electrons

• gains protons

• loses electrons

• loses electrons or gains protons

Which subatomic part of an atom gives it a positive charge?

• Neutron

• Proton

• Electron

• Nucleus

What is the smallest 'building block' of the elements that make up the universe?

• An atom

• An electron

• A proton

• A cell

A chemical compound is

• a substance formed by the chemical bonding of two or more different elements

• a substance formed by the chemical bonding of two or more atoms

• oxygen gas, O₂

• usually has identical physical and chemical properties to those elements from which it is formed.

Some molecules are compounds, but not ALL molecules are compounds.

• True

• False

What two sub-atomic particles are found in the nucleus of an atom?

• Neutrons and Protons

• Shells and Electrons

• Electrons and Protons

• Electrons and Neutrons

Valence electrons are: 

• Electrons farthest away from the nucleus
• Electrons closest to the nucleus
• Electrons that just come and go - they don't stay with the atom

Two or more atoms chemically bonded together are called a

• atom
• element
• molecule
• mixture