Bio Chapter 2 vocab

Element

Element

A substance that cannot be broken down chemically into any other substances

Atoms

Individual component pieces of an element

Nucleus

The part of an atom that is in the center

Protons

Particles that have a positive electrical charge

Neutrons

Particles that have no electrical charge

Mass

The amount of matter in an object

Electrons

Negatively charged particles whirling in a cloud around the nucleus

Atomic mass

The mass of an atom

Atomic number

The number of protons an atom of a particular element has

Isotopes

Atoms with the same number of protons but different numbers of neutrons

Radioactive

Atoms with unstable nuclei that break down spontaneously sometimes after they are created

Periodic table

All the known elements arranged in numerical order of how many protons they have

Ion

A charged atom

Molecules

Groups of atoms held together by bonds

Bond energy

The amount of energy need to break a bond between two atoms

Covalent bond

A bond formed when two atoms share electrons

Double bond

The sharing of two pairs of elctrons between two atoms

Ionic bond

A bond that occurs when oppositely charged ions attract each other

Ionic compound

Ions of two or more elements linked by ionic bonds

Hydrogen bond

A bond formed between a hydrogen atom in one molecule and another atom, often an oxygen or nitrogen atom, in another molecule

Polar

Having an electrical charge

Cohesion

The sticking together of particles of the same substance. The inter connection of water molecules through hydrogen bonds is what makes water experience this property

Heat capacity

The amount of energy needed to raise a substance’s temperature. This is why it takes more heat to heat up water than other substances

Density

Mass of an object divided by its volume.

Solvent

It breaks ionic bonds by pulling the atoms apart since its charged. Water is a good example of one these

Solute

A substance that is dissolved in a gas or liquid

Nonpolar

Electrically uncharged

pH

a measure of a substance’s acidity

Acid

Any fluid with a pH below 7.0

Base

Any fluid with a pH above 7.0

Buffers

Chemicals that can quickly absorb H+ ions to keep a solution from becoming too acidic and can quickly release H+ ions to counteract any increases in OH- concentration.