Properties of Water and Molecules

Why do butter and water not mix well?

• Butter is heavier than water.

• Water is polar and butter is nonpolar.

• Butter is a solid and water is a liquid.

• Water molecules are too small to mix with butter.

What does electronegativity tell us about an atom?

• How big the atom is.

• How much the atom attracts shared electrons.

• The color of the atom.

• How easily the atom melts.

What two things are needed for a molecule to be polar?

• It must be made of only one type of element and have a symmetrical shape.

• It must have an uneven sharing of electrons and an asymmetrical shape.

• It must be a gas and have a symmetrical shape.

• It must be made of two different elements and have a symmetrical shape.

What kind of substances do polar liquids, like water, usually dissolve well?

• Substances that are nonpolar.

• Substances that are also polar or ionic.

• Gases only.

• Metals only.

What helps water stay piled up above the rim of a glass?

• Gravity pulling it down.

• The glass pushing it up.

• Water molecules sticking together.

• Air pressure pushing it down.

Why do oil and water separate when mixed?

• Oil is heavier than water.

• Water molecules like to stick to each other more than to oil.

• Oil molecules are too big to mix with water.

• Water and oil are different colors.

How does water dissolve salt?

• Water heats up the salt until it melts.

• Water molecules break the salt into tiny pieces.

• The positive and negative parts of water molecules pull apart the salt's charged pieces.

• Salt disappears when it touches water.

Why does ice float on water?

• Ice is lighter than water.

• The coldness of ice makes it rise.

• Water molecules in ice are spread out more than in liquid water.

• Ice has air bubbles trapped inside it.