Basic Chemistry

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.

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A covalent bond forms

• when one or more electrons are transferred from one atom to another.

• when electrons are shared between atoms.

When is an ionic bond formed?

• when electrons are shared

• when protons are shared

• when oppositely charged atoms gain or lose electrons

• when oppositely charged atoms gain or lose protons

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Bond created by the sharing of electrons

• Ionic Bond
• Hydrogen Bond
• Covalent Bond
• van der Waals

An atom becomes a positive ion when it

• gains electrons

• gains protons

• loses electrons

• loses electrons or gains protons

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

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An atom of carbon has 6 protons and 7 neutrons in its nucleus. If the atom is neutral, how many electrons does it have?

• 0

• 7

• 6

• 13

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A substance with a pH of 8 is a

• acid

• base

• neutral

Carbon has 4 valence electrons which means

• it can only form bonds with carbon

• it is stable

• it can make ionic bonds

• it wants to make 4 covalent bonds

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Acids have more ______ ions than bases

• OH^-

• H^-

• OH⁺

• H⁺