Elements, Compounds, and Mixtures

Flashcards covering key vocabulary from the lecture notes on Elements, Compounds, and Mixtures.

Periodic Table

Elements are sorted into metals, non-metals, and metalloids based on their properties.

Groups

There are 18 columns in the periodic table.

Periods

There are 7 rows in the periodic table.

States of Matter

Solid, liquid, and gas.

Melting

The change of state from solid to liquid.

Evaporating

The change of state from liquid to gas.

Freezing

The change of state from liquid to solid.

Condensing

The change of state from gas to liquid.

Particle Model

Substances are made up of tiny particles that are attracted to each other and always moving.

Atoms

Smallest unit of matter.

Protons

Positively charged particles in the nucleus.

Neutrons

Neutral particles in the nucleus.

Electrons

Negatively charged particles orbiting the nucleus.

Atomic Number

The number of protons in an atom, which determines its element.

Number of Electrons

Determined by the number of protons.

Number of Neutrons

Mass number – atomic number.

Metals

Solid at room temperature (except Hg), shiny, conduct heat and electricity, malleable, ductile, and high melting points (except Hg).

Non-metals

Cannot be polished, brittle, low melting point (many are gases at room temperature).

Metalloids

Have some properties of metals and non-metals.

Alkali Metals

VERY reactive in water and are in group 1.

Alkaline Earth Metals

Less reactive than alkali metals and are in group 2.

Transition Metals

Found in groups 3 to 12 with many interesting properties and colorful compounds.

Halogens

Very reactive elements found in group 17.

Noble Gases

Unreactive elements found in group 18. They glow when exposed to electricity.

Elements

Pure substances made of only one type of atom, having a name and a symbol.

Compounds

Substances that are made up of metals and non-metals are just called compounds.

Mixtures

Two or more substances mix but do not form chemical bonds; retains properties of individual parts.

Molecules

A group of atoms bonded together

Lattices

Compounds metals and non-metals arranged into giant grids, where each atom lines up one after another, repeating the same pattern over and over

Chemical Change

Change in which bonds between atoms and molecules are broken and new bonds are formed; not easily reversible.

Physical Change

Can be observed using senses or measured directly; reversible.

Chemical Reaction

Chemical change in which a new substance is made; products have different chemical properties than reactants.

Chemical properties

Flammability, reactivity, and toxicity.

Evidence of a Chemical Reaction

A precipitate is formed, an odor, bubbles/gases are released, light/heat is released, a change of color, or a change in mass.

Reactants

What you begin with in a chemical reaction

Products

New substances formed in a reaction.

Indigenous Knowledge

Describes the element, compound, or mixture that Indigenous Australians used (ochre pigments, plant medicines) and its composition and source.

How do you determine the electrodes in an element.

Atomic Weight - Atomic Number

FE

Iron

AU

Gold

AG

Silver

HG

Mercury

Groups 3-12

Transition Metals

K₂SO₄

2 Potassium, 1 Sulfur, 4 Oxygen

Transition Metals

Good Conductors of heat and electricity

Transition Metals

Malleable

Transition Metals

High melting points (except Hg)

Nucleus of an Atom

Neutrons and Protons

Charge of a Neutron

neutral

Mass of electron

1/1800

Mass of Protons and Neutrons

1