Chemistry Unit One Test

Front 1

What is an element

Back 1

Pure substances made of identical particles called atoms

Front 2

Example of a physical property

Back 2

Can be observed without changing the identity of the substance

- colour, shiny or dull, taste, smell, soft or hard, brittle or malleable, density, etc.

Front 3

Example of a chemical property

Back 3

*Can only be observed when a substance's identity is changed

Front 4

What is the periodic table?

Back 4

A collection of all the known elements (like the alphabet of chemistry) in order of their atomic number

- Each group is similar by property

- Each period has atoms that get heaving from left to right and show gradual change between metallic and non-metallic properties

Front 5

Explain what each of the numbers refer to

Back 5

1) Atomic number

2) Electronegativity

3) Common ion charge

4) Other ion charge

5) Symbol of element

6) Name of element

7) Atomic mass

Front 6

Give a four point history of the development of the periodic table

Back 6

1) Dobereiner identified triads - groups of three elements with similar properties are equidistant to each other in mass

2) Newland's discovered properties repeated every 8 elements when listed by mass. Called this the law of octaves

3) Lother Meyer arranged the periodic table similiar to Mendeleev, but only described what was known

4) Mendeleev defined periodic law. Left numerous blanks in his table to be discovered later

Front 7

State Mendeleev's periodic law

Back 7

"The properties on the elements are a periodic function of their atomic masses"

Front 8

State the periodic law that we use today

Back 8

When elements are arranged in order of increasing atomic number, their properties show a periodic recurrence and a gradual change

Front 9

What are the three main sections of the periodic table?

Back 9

1) Metals

2) Metalloids

3) Non-metals

Front 10

Explain the difference between a period and a group

Back 10

Each group is similar by property

Each period has atoms that get heavier from left to right, and show gradual change from metallic to nonmetallic properties

Front 11

List the properties of Alkali Metals

Back 11

- Shiny and soft

- Compounds are colourless and soluble

- Very reactive (*reactivity increases down the group)

- Bases form when mixed with water

Front 12

List the properties of Alkaline Earth Metals

Back 12

- Harder than alkali metals (compounds are not as soluble

- Bases form when mixed with water

Front 13

List the properties of Transition Metals

Back 13

Complex metals

Colourful compounds

Front 14

List the properties of Lanthanides and Actinides

Back 14

- Transition metals

- Belong to periods 6 and 7

Front 15

List the properties of Halogens

Back 15

- Complex metals

- Colourful compounds

Front 16

List the properties of Noble Gases

Back 16

- All gases

- Colourless

- Extremely non-reactive / inert

Front 17

What is an atom?

Back 17

The smallest unit of an element that retains it properties. All atoms of the same element have identical number of protons

Front 18

Give a four point history of the atomic model

- explain each scientists model

Back 18

- Dalton considered the atom to be a featureless sphere, but contained different matter from atom to atom

- Thompson discovered electrons and incorporated the idea of charges into an atomic model

- Rutherford discovered that atoms had a nucleus that contained protons and neutrons

- Bohr organized the electrons into definite energy shells

Front 19

What is an isotope?

Back 19

A specific mass variety of an atom from an element

- a particular number of neutrons

Front 20

How do you calculate the number of neutrons in an isotope?

Back 20

Atomic mass minus the number of protons equals the number of neutrons

Front 21

Explain the difference between atomic number, atomic mass, and mass number

Back 21

Atomic number - the number of protons inside the atom

Atomic mass - the sum of the number of protons and neutrons (averaged)

Mass number - The mass of a specific isotope. A whole number (not averaged). The total number of protons and neutrons

Front 22

What is a radioisotope?

Back 22

Unstable isotopes that give off radiation

Very heavy; the nucleus splits up "fission"

Front 23

What is an ion?

Back 23

Ions are atoms of the same element that have the same number of protons, but have more or less electrons than a neutral atom, and so have a charge

Front 24

Explain how and why metals become positive ions

Back 24

Metals lose electrons to empty their other shell and become positively charged. They have a positive charge because they have more protons than electrons

Front 25

Explain how and why nonmetals become negative ions

Back 25

Nonmetals gain electrons to fill its outer shell and become negatively charge. They have a negative charge because they have more electrons than protons

Front 26

Where do you find the most reactive metal and the most reactive non-metal?

Back 26

Metals - Larger group one and two metals are more reactive that smaller ones. The further away the valence shell is away from the nucleus, the easier it is to give away electrons

Nonmetals - Fluorine is the most reactive element because it is trying to complete its only octet

Front 27

Where do you find the biggest atom in the first group?

Back 27

Size increases down a group

Front 28

Where do you find the most electronegative element?

Back 28

Fluorine is the most electronegative element (How much an element wants an electron)

Fluorine's electronegativity is 4.0

Front 29

What is an ionic bond?

Back 29

A metal transfers one or more electrons

This results in a positive metal ion (cation) and a negative non-metal (anion)

Opposite charges attract

Front 30

What is an ionic compound?

Back 30

Neutral compound

Often called salts

Semi-permanent electrostatic attraction

Form a crystal lattice structure

Can be broken up chemically or physically

Front 31

List the properties of ionic compounds

Back 31

- High boiling point, high melting point

- Brittle solids at room temperature

- Tend to dissolve well in water

- Make electrolyte solutions when dissolved in water

Front 32

How do you determine the formula for an ionic compound?

Back 32

Criss cross method

The charge of each ion becomes the quantity needed of the opposite ion

Reduce if necessary

Front 33

How do you name an ionic compound?

Back 33

Name the metal

Include the charges as a roman numeral if the metal is multivalent

Name the non-metal ending in "ide"

Front 34

When and why do we use roman numerals in names?

Back 34

Some ionic compounds have a metal that is multivalent

- meaning more than one possible charge

A roman numeral is used to specify which charge is used

Front 35

What is a polyatomic ion?

Back 35

A covalently bonded cluster of elements (usually nonmetals) that have an overall charge

Because of this charge, it is not considered a molecule

Ions made of more than one atom

Front 36

How can you tell if a compound has a polyatomic ion in it?

Back 36

The polyatomic ion enters ionic bonds as a cluster. It is never broken up

Front 37

When and why do we use brackets in a formula?

Back 37

Brackets show that there are multiples of the whole polyatomic ion, not just the last atom in it

Front 38

What is a covalent bond?

Back 38

Two nonmetals sharing 2, 4, or 6 electrons so each atom has access to 8 electrons

Front 39

What is a molecular compound? (a molecule)

Back 39

A molecular compound is made of nonmetals with more than one covalent bonds

Front 40

List the properties of molecular substances

Back 40

- lower melting points

- liquids or gases at room temperature

- non-electrolytes in water

- less soluble, and when they do not dissolve, the covalent bonds are not broken

Front 41

How and why does the naming of molecular compounds differ from the naming of ionic compounds?

Back 41

Molecular compounds include a prefix

Repeat for the second element, end in "ide"

Do not criss cross the charges

Do not reduce the ratio