Chemistry

chem

20 cards·by stewarde2

Atom

smallest particle of a substance that can only exist by itself or be combined with other atoms to from a molecule.

Element

One of the basic substances that are made of atoms of one kind and cannot be separated into simpler substances.

Proton-

very small particle of matter that is part of the nucleus of an atom.

Neutron-

- very small particle of matter that has no electrical charge and is part of all atoms except hydrogen

Atomic mass

number of protons and neutrons of an atom (an average).

Compound

substance formed when two or more elements are chemically bonded together.

Nucleus

the positively charged central core of an atom, consisting of protons, neutrons and containing most of the mass.

Ionic bond

when a positively charged ion forms a bond with a negatively charged ion and one atom transfers the electron to another.

Covalent bond

chemical bond that involves sharing of electron pairs between atoms.

Chemical equation

a symbolic representation of a chemical reaction in the form of symbols and formulas.

Product

substances produced by the reaction on the right-hand side of the chemical equation.

Subscripts

a number that follows the elements, usually written lower, that represents the number of atoms in a compound.

Metals

any chemical element that is an effective conductor of electricity and heat.

Homogenous mixture

a mixture that is uniform in composition throughout.

Heterogeneous mixture

a combination two or more pure substances that retain their chemical properties.

Yield sign

- an arrow that separates the two sides of a chemical equation

Period

a horizontal row of the periodic table.

Group

a column of elements on the t=periodic table that have similar characteristics.

Reactant

a substance that takes part in and undergoes change during a reaction.

Atomic number

the number of protons in the nucleus of an atom. It determines the chemical properties of an element and its place on the periodic table.