10 Physical Science T1 (Chemistry)

Atomic Theory + Ionic and Covalent Bonding

atom

Smallest unit of matter

Element

Pure substance made up of only one type of atom

Compound

Substance made up of two or more different atoms bonded together

Mixture

Two or more substances (elements or compounds) combined but not chemically bonded

Molecule

Substances made up of two or more atoms bonded together

Diatomic elements

Elements found in twos

Physical change

A change in matter which does not alter the chemical properties of the matter.

Exothermic

A reaction or process accompanied by the release of heat.

Endothermic

A reaction or process accompanied by or requiring the absorption of heat

Period

a set of elements occupying a horizontal row in the periodic table.

Group

a column in the periodic table of the chemical elements

Proton

a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron.

Neutron

a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen

Electron

a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

Nucleus

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

Isotope

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

atomic number

the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.

mass number

the total number of protons and neutrons in a nucleus.

Ion

an atom or molecule with a net electric charge due to the loss or gain of one or more electrons

Ionic compound

compounds made up of ions that form charged particles when an atom (or group of atoms) gains or loses electrons

Electrostatic charge

a deficiency or excess of electrons which occurs on ungrounded or insulating surfaces

Cation

Positive ion

Anion

Negative ion

Heterogenous

Mixture that is not the same all the way through (non-uniform composition)

Homogenous

Mixture that is the same all the way through (uniform composition)

Chemical change

the properties of the new substances are different from the original, the particles are different, and the number of particles can change

Ionic Bond

type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound

single bond

A chemical bond in which one pair of electrons is shared between two atoms. One atom may form multiple single bonds

double bond

When two pairs of electrons are shared a double covalent bond is created. This is represented by two lines in a Lewis Dot diagram. In some cases, a variety of covalent bonds exist within a single molecule

triple bond

When three pairs of electrons are shared a triple covalent bond is created. This is represented by three lines in a Lewis Dot diagrams

alkali metals

Low melting and boiling points, Soft and shiny, for cations with charges of +1, one valence electron, react violently with water, Reactivity increases as you move down the table

halogens

Very reactive (7 valence electrons), Gases (highly toxic), Form -1 charged anions, Diatomic – exist as two atoms, decrease in reactivity as you move down the table

noble gases

all gases, odorless, colourless, complete set of valence electrons (8e- therefore not reactive), extremely low chemical reactivity

covalent bond

consists of the mutual sharing of one or more pairs of electrons between two atoms

coefficient

a multiplier or factor that measures a particular property.

Decomposition

the state or process of rotting; decay.

Combination

a joining or merging of different parts or qualities in which the component elements are individually distinct

Combustion

rapid chemical combination of a substance with oxygen, involving the production of heat and light.

Insoluble

(of a substance) incapable of being dissolved.

Soluble

(of a substance) able to be dissolved, especially in water.

Precipitation

the action or process of precipitating a substance from a solution.

Double displacement

a chemical reaction where two reactant ionic compounds exchange ions to form two new product compounds with the same ions.

Single displacement

a reaction in which one element is substituted for another element in a compound

corrosion

a natural process that converts a refined metal into a more chemically stable oxide

Product

a substance that is present at the end of a chemical reaction

Reactant

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

Chemical reaction

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

Covalent compound

A compound whose atoms are bonded via a covalent bond

Ionic compound

neutral compounds made up of positively charged ions called cations and negatively charged ions called anions.