Chemistry Exam Review Flashcards

Flashcards on Chemistry Exam Review

Pure substance

A substance that is made up of only one type of particle.

Mixture

A substance that is made up of more than one type of particle.

Solution

A uniform mixture of two or more substances where you can only see one phase.

Mechanical mixture

A mixture in which you can distinguish between different types of matter.

Alloy

A solid solution of two or more metals.

Physical property

A characteristic of a substance that can be determined without changing its composition.

Qualitative property

A property of a substance that is not measured and does not have a numerical value.

Quantitative property

A property of a substance that is measured and has a numerical value.

Physical change

A change in which the composition of the substance remains unaltered.

Chemical property

A characteristic of a substance that is determined when the composition of the substance changes.

Chemical change

A change in the starting substance(s) and the production of one or more new substances.

Density

The mass per unit volume of a substance.

Element

A pure substance that cannot be broken down into a simpler chemical substance by any physical or chemical means.

Compound

A pure substance composed of two or more different elements that are chemically joined.

Atomic number

The number of protons in an atom’s nucleus.

Mass number

The total number of protons and neutrons in the nucleus of an atom.

Ancient Greeks

• The first concept of the atom can be traced back to them

• the word atom comes from the Greek Atomos, meaning indivisible.

• Democritus reasoned that if you broke matter down into smaller pieces, you would eventually reach the point where it could not be broken down any further

Alchemists

• Their major contribution to atomic theory was technological advances which allowed for the development of modern science.

• lab glassware and equipment, alloys, handling procedures for dangerous chemicals

Dalton's Atomic Model

Suggested that atoms were solid, indivisible spheres; main problem was that his theory did not address how things acquire electrical charge.

Thomson's Atomic Model

Atoms were composed of a uniform positive charge, with negatively charged electrons embedded in them. Positive charge was not uniformly distributed, nor were electrons simply embedded within the atom.

Rutherford's Atomic Model

Proposed the nuclear model of the atom. The atom has a very small, heavy nucleus (protons) surrounded by electrons; most of the atom is empty space; model did not adequately address electron behaviour.

Bohr's Atomic Model

Similar model to Rutherford, except that electrons are found in fixed energy levels around the nucleus.

Chadwick

Discovered the neutron.

Test for hydrogen gas

a burning splint that produces a "popping" sound

Test for oxygen gas

a glowing splint that bursts into flames

Test for carbon dioxide

Limewater mixed with the gas turns milky

metal that s liquid at room temp

Mercury

Metals that are not silver in colour

Gold and copper

Metals that are magnetic

Iron(Fe), cobalt(Co), nickel(Ni), neodymium(Nd)

Characteristic of silicon

Solid, silver, brittle, lustre, semi conducter, not magnetic

Non-Metal that is a conductor

Graphite

clues of a chemical change

• change of colour

• bubbles of gas produced

• heat and/or light is released or absorbed

• change of odour

• a precipitate is produced

How to draw Bohr-Rutherford diagrams

• Wrting the number of protons and neutrons as #p #n in a circle in the middle

• Drawing the electrons on rings in the order 2,8,8,2

Sublimation

Solid-Gas

Depostion

Gas-solid