Science 10 - Chemistry - Part 1

All matter is composed of combinations of fire, water, air, and earth (400 BC)

All matter is composed of tiny particles that could not be divided (400 BC, less popular theory)

Everything was made up of atoms which looked like tiny spheres (Billiard Model) which varied in properties. Proposed particle theory

Discovered the electron. Developed Plum Pudding model of the atom which involved the electron.

Discovered nucleus of an atom, discovered via the gold foil experiment. Concluded majority of the atom was empty space. Developed the Nuclear Model.

Proposed electrons surround the nucleus at various energy levels (shells). Developed the Planetary/Bohr Model.

Proposed electrons exist in electron clouds (orbitals), not specific energy levels, using quantum mechanics. Developed Electron Cloud Model

Solid sphere to represent atoms

Positive sphere dotted with negatively charged areas (electrons)

Distinguished nucleus in the center, surrounded by electrons

Distinguished nucleus in the center, surrounded by energy levels of electrons that followed 2, 8, 8 rule

Distinguished nucleus in the center with areas of electrons surrounding it

1. Matter is made up of tiny particles

2. Particles are in constant motion

3. Held together by forces (Bonds)

4. Particles have empty space between them

1. Pure Substances (Elements, Compounds)

2. Mixtures (Homogeneous, Heterogeneous)

Can exist as atoms or molecules (singular atoms vs multiple atoms). Basic unit, cannot be broken down further

A change in the number of electrons in an atom (Can be positive or negative through loss or gain of an electron)

A change in the number of neutrons in an atom’s nucelus

2 or more elements (ions/atoms) bonded together. Can be molecular or ionic (2 non-metals vs 1 non-metal and 1 metal)

1 negative non-metal (anion) and 1 positive metal (cation) bonded together through transfer of electrons. Include bonded polyatomics. (Properties: High melting points, high conductivity, solid at room temperature, most water soluble, can form precipitates)

Solid substance in a solution

2 non-metals bonded together through the sharing of electrons. (Properties: Low melting points, low conductivity, can be any state at room temp, low water solubility)

Water

Glucose

Ozone

Hydrogen Peroxide

Ammonia

Sucrose

Methane

Propane

Methanol

Ethanol

Hydrogen Sulfide or Hydrosulfurous Acid

Elements that are naturally found as molecules (multiple). Include I, Br, Cl, F, O, N, H + P4, S8

Developed by Mendeleev to organize various discovered elements. Composed of 16 groups (vertical) and 7 periods/families (horizontal)

Found on left/middle of periodic table. Elements that conduct heat/electricity, are malleable, ductile, and lustrous

Found in area around staircase. Share properties of metals and non-metals

Found on right side of periodic table, above staircase. Elements are non-conductive and brittle as solids

Horizontal organization of elements, based on increasing atomic number from left to right.

Vertical organization of elements, elements in the same group have the same number of valence electrons and thus similar reactivity

Group 1 on the periodic table. Very reactive with water/water soluble. Have 1 valence electron, more reactive going down the group.

Group 2 on the periodic table. Have 2 valence electrons, tend to for 2+ ions.

Group 17 on the periodic table. Readily reacts with Alkali Metals ti form salts. Has 7 valence electrons, more reactive going up the group

Group 18 on the periodic table. Very unreactive with other elements due to full valence shells.

Diagrams that show only the valence electrons around the element symbol

Refers to the ability of a substance (solute) to form a solution

Soluble in water

Measurement of how acidic or basic a substance is

A substance with a pH lower than 7. Involve H⁺ ions, H at beginning (or at end if COO). Molecular substances, water soluble, conductive, corrodes metals

A substance with a pH greater than 7. Involves OH^- ions or ammonium. Molecular or ionic substances, water soluble, conductive

Substances with pH’s exactly at 7.

Tests used to identify if a substance is an acid or base. (ie litmus paper)

Reaction between acids and bases that results in a pH of 7. H⁺ ions must react with OH^- ions to create water, ionic salts are also produced