Chemistry test - Matter and Cah

Compound

A substance that can be separated into simpler substances only by chemical reactions. They consist of two or more elements.

Mixture

Physical blend of two or more substances that can be physically separated into its components.

Solution

Homogenous mixtures are called solutions

Matter

Anything that has mass and takes up space

Mass

The amount of matter that an object contains

Weight

The measure of the force of gravity acting on a body

Volume

The amount of space the object takes up

Extensive property

Property depending on the amount of matter in a sample

Intensive property

Property depending on the type of matter in a sample

Substance

Matter that has a uniform and definite composition

Pure Substance

Contains only one type of matter (salt, glucose, etc)

Homogeneous Mixtures

has a completely uniform composition. Its components arenot readily distinguished. Consists of a single phase

Heterogeneous Mixtures

Not uniform in composition. Its components are readily distinguishable. Consists of two or more phases

Element

A substance that cannot be broken down into simpler substances under normal laboratory conditions. They are the simplest forms of matter

characteristics of solid gas and liquids

	Solid	Liquid	Gas
Arrangement	- Particles contact each other - Rigid arrangement	- Particles contact each other - Not a rigid arrangement	- Slight contact - Spread more thinly
Definite Volume	Yes	Yes	No
Definite Shape	Yes	No	No
Fluid (flows)	No	Yes	Yes
Expansion When Heated	Slight	Moderate	Greatly
Compressible	No	No	Yes
Vapor - a substance in its gaseous state that is ordinarily a liquid or solid at room temperature.

Physical Properties

• The condition or quality of a substance that can be measured or observed without changing the composition of a substance. 

• Examples: 

  • Hardness

  • Color

  • Conductivity

  • Malleability

  • Density

  • Melting point

  • Solubility

Chemical Properties

• Ability of a substance to undergo a chemical reaction and to form new substances.

• Only observed when a substance undergoes a chemical change and results in a change of the chemical composition of the substances involved

Physical Changes

• A change that alters the given material without changing its composition.

• Changes in state usually have to do with changes in temperature.

• Usually reversible

Atomic number

total number of protons in the nucleus of an element.

Atomic mass unit

1/12th the mass of a carbon-12 atom

Atomic mass

the weighted average mass in a naturally occurring sample of an element.

Mass number

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

Groups (families)

•  - the columns 

  • Same number of valence electrons

  • They share similar chemical and physical properties

Periods

•  - rows

  • Share the same amount of electrons shells

  • There are 7 periods

Groups

• Alkali Metals

  • The alkali metals are the elements that belong to group 1 (IA) of the periodic table.

  • The alkali metals are all shiny, soft, low density, highly reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge +1.

• Alkali Earth Metals

  • The alkali earth metals are the elements that belong to group 2 (IIA) on the periodic table.

  • They are all shiny, silvery-white, soft, low density somewhat reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge +2.

• Transition Metals

  • They are Group B elements.

  • They are high density, hard, have high melting and boiling points, produce stable complexes, and display variable oxidation states.

• Isosagens

  • The Isosagens are the elements that belong to group 13 (IIIA) of the periodic table (the boron family).

• Tetragens

  • The Tetragens are the elements that belong to group 14 (IV) of the periodic table (the carbon family).

• Pnictogens

  • The Pnictogens are the elements that belong to group 15 (VA) of the periodic table (the nitrogen family).

• Chalcogens

  • The Chalcogens are the elements that belong to group 16 (VIA) of the periodic table (the oxygen family).

• Halogens

  • The Halogens are the elements that belong to group 17 (VIIA) of the periodic table (the flourine family).

  • No non-metals

  • Highly reactive

• Noble Gases

  • The Noble gases are the elements that belong to group 18 (VIIIA) of the periodic table.

  • They are all odorless, colorless, monatomic gasses, and nonmetal with very low chemical reactivity.

Particle History

Dalton: Everything is composed of atoms. All atoms of an element are identical The atoms of different elements vary in size and mass. Compounds are produced through different whole-number combinations of atoms. A chemical reaction results in the rearrangement of atoms in the reactant and product compounds. Thomson: He studied cathode rays and came up with the idea of an electron (e-), a negatively charged, subatomic particle. Millikan: His oil drop experiment measured the charge of an electron. Rutherford: Gold foil experiment led to the discovery of the proton. The volume occupied by an atom must consist of a large amount of empty space. A small, relatively heavy, positively charged body, the nucleus, must be at the center of each atom where most of the mass of the atom is concentrated. Bohr: Postulated electrons travel in discrete orbits around the nucleus. Chadwick: Discovered the neutron and was found to measure slightly heavier than the proton and with a neutral charge. The proton and neutron together were called the nucleus. Periodic Table History Mendeleev: Arranged the elements known at the time in order of relative atomic mass. Moseley He rearranged the periodic table by using the atomic number instead of atomic mass to represent the progression of the elements.