Biology Unit 2 (Group A)

Front

The smallest basic unit of matter.

Back

Atom

Front

a substance made up of one type of atom and cannot be broken into simpler substances by ordinary chemical means.

Back

Element

Front

two or more atoms held together by a covalent bond.

Back

Molecule

Front

forms when atoms in the molecule have unequal pulls on the electrons they share. So that one side of the molecule becomes slightly charged positively and the other is slightly negatively charged.

Back

Polar molecule

Front

When a hydrogen atom is part of a polar molecule, the hydrogen atom has a slight positive charge.  This slightly positive atom is attracted to a slightly negative atom, often oxygen or nitrogen, forming a hydrogen bond. Life depends on hydrogen bonds!!

Back

Hydrogen Bond

Front

The formation of hydrogen bonds allows water molecules to stick to each other.

Back

Cohesion

Front

The formation of hydrogen bonds that allows water molecules to stick to other things.

Back

Adhesion

Front

Adhesion and cohesion work together to move water up a narrow tube against gravity.

Back

Capillary action

Front

Water can absorb a lot of heat energy without raising its temperature, due to hydrogen bonding between molecules.

Back

High heat capacity

Front

Water evaporating off the surface of an object lowers the temperature on the surface from which the liquid is evaporating.

Back

Evaporative cooling