Chem. Vocab. Test Review

Physical Properties

traits that can be observed or measured without changing the composition of matter.

Chemical Propterties

how a substance will react with another substance to form new materials.

Elements

A pure substance that cannot be broken down into simpler parts.

Atoms

Tiny particles in an element

Protons

Subatomic particles with a positive charge that are found within the middle center (nucleus) of an atom.

Neutrons

Subatomic particles without charge, also found within the nucleus of an atom.

Electrons

Subatomic particles with a negative charge, found in circular pathways (orbits) around the nucleus of an atom.

Periodic Table

Used to represent all elements in existence.

Element Symbol

composed of either one or two letters of the alphabet, beginning with a capital letter, second letter as lowercase.

Atomic number

Equal to the number of protons in the nucleus of an atom of that element.

Atomic Mass

Equal to the combined mass of all the protons and neutrons.

Valence Electrons

All electrons found on the outer shell of atoms.

Periods

rows of the periodic table, al elements do not have similar chemical properties.

Groups

columns of the periodic table, all elements have similar chemical properties.

Families

A group with a specific name. Alkali metals, alkaline metals, chalcogens, halogens, noble gases.

Alkali Metals

group 1, has 1 valence electron, soft and highly reactive metals.

Alkaline Metals

group 2, less reactive than alkali, has 2 valence electrons.

Chalcogens

group 16, non-metals, less reactive than halogens, has 6 valence electrons.

Halogens

group 17, poisonous and highly reactive non-metals, has 7 valence electrons

noble gases

group 18, very stable non-metals, unreactive, has 8 valence electrons.

hydrogen

non-metal gas, has 1 electron, highly reactive

metals

shiny in appearance, malleable, ductiable

metalloids

shiny in appearance, poor conductors of heat, non-malleable.

non-metals

dull in appearance, poor conductors of heat, not ductile.

matter

anything that has mass and takes up space/volume.

pure substance

a substance that is made up of the same type of particles.

mixture

a substance that is made of more than 1 element.

compound

the simplist form of any material containing 2 or more elements.

heterogeneous mixture

a substance with particles that are not evenly distributed; individual particles can be found.

homogeneous mixture

a substance with particles that are evenly distributed; cannot be easily seperated.

chemical reaction

a movement of electrons between combining atoms that results in the formation of a new substance.

chemical formula

used to show in an element of compound, the types of atoms present, and amounts of each type of atom present.

Law of Conservation of Matter

states that in any chemical reaction, matter cannot be created nor destroyed; atoms can only be rearranged to form new compounds.

physical change

A change in shape or a change in the state of a substance.

chemical change

when new substances with new properties are formed.

combustion

when a substance reacts rapidly with oxygen, and releases energy.

corrosion

when a metal reacts with oxygen from the air to form a new substance called an oxide.