Chapter 5 - Elements

Question 1

What is the Atomic Theory?

Answer 1

• All matter is made of small, indivisible particles called atoms
• All the atoms of an element are identical in properties such as size and mass
• Atoms of different elements have different properties
• Atoms of different elements can combine in specific ways to form new substances

Question 2

What is a Bohr model or Bohr diagram?

Answer 2

A diagram that shows the nucleus, and the orbiting electrons.
Also includes indications such as “2p 2n” on the nucleus area.

The most inner orbit has up to 2 electrons,
The other orbits are all up to 8.

in pairs

Question 3

What are the symbols of protons, neutrons, and electrons?

What are their relative masses?

Answer 3

p, n, e

Relative mass:
Proton 1836
Neutron 1837
Electron 1

Proton 1 amu
Neutron 1 amu
Electron Neglible

amu = atomic mass unit

Question 4

Name some physical properties for metals.

Answer 4

Metals are mostly shiny, and silver or grey. They are good conductors of electricity and heat. Malleable and ductile.

Question 5

Non-Metals vary in properties. What are some non-metal solids?

Answer 5

Sulphur.

Does not comply with properties of metal and is reactive and will burn in air to produce a poisonous gas.

Question 6

What is the most common metalloid?

Answer 6

The most common metalloid is silicon.

Question 7

iron (Fe) + carbon (C) = ?

Answer 7

iron (Fe) + carbon (C) = STEEL

Steel is fairly resistant to corrosion.

Question 8

List some properties of iron (Fe).

Answer 8

Plain iron corrodes easily in moist air.
Silver-grey, can be molded and shaped when heated.
Hard enough to keep a sharp edge.

Question 9

List some properties of carbon (C).

Answer 9

Graphite and diamond are both forms of carbon.

Your body and the food you eat contain many different carbon compounds.

Question 10

List some properties of hydrogen (H).

Answer 10

Hydrogen is the most common element in the universe.
Lightest and simplest of all atoms.
On earth, almost all of the hydrogen that is present is in water.
Pure hydrogen is colourless, odourless, and lighter than air.
Extremely FLAMMABLE.

Question 11

List some properties of oxygen (O).

Answer 11

21% of the air we breathe.
Oxygen gas; ozone (toxic to breathe).
Most common element on earth’s surface.
Makes up more than 50% in rocks, combining with silicon (both are a major part of glass).

Question 12

List some properties of sodium (Na).

Answer 12

Metal
Conducts electricity, is shiny, silver-grey, malleable, and ductile.
Sodium metal burns in air.
Soft, melting point of 98°C.

Pure sodium metal is usually stored in oil.

Question 13

List some properties of chlorine (Cl).

Answer 13

Non-metal.
Yellow-green gas at room temperature.
High concentrations of chlorine gas are focus and destroys lung tissue quickly.

Used at lower concentrations as a disinfectant.

Question 14

What is the atomic number? (Smaller number)

Answer 14

Atom number is the number of protons in an atom of an element.

Question 15

What is atomic mass? (Larger number)

Answer 15

Atomic mass = protons + neutrons

measured in amu

Question 16

What is an ion?

Answer 16

An ion is an atom or group of atoms that has lost or gained electrons.

Question 17

Period/Group?

Answer 17

Period - horizontal

Group/chemical family - vertical

Question 18

List the similarities in alkali metals.

Answer 18

Silver-grey, malleable and ductile, and conduct electricity and heat.
LOW melting points.
React easily with water and air.

Question 19

List the similarities in halogens.

Answer 19

Non-metals
Noticeable colours!
Bromine (liquid) and iodine (solid) at room temperature turn into gases with slight heating, like other halogens.
Very reactive.
Chlorine, bromine, and iodine can all be used as disinfectants.

Question 20

List the similarities in noble gases.

Answer 20

All exist naturally as colourless gases.
Will glow with bright colours if an electric current is passed through them, as in a neon light.

NONE of these gases is chemically reactive e cost in certain special situations.

Question 21

What is another name for shells? (Orbit outside the nucleus)

Answer 21

Another name for shells is energy levels.

Question 22

Group 1 (Alkali metals) have what in common because of their similar valence electron arrangements?

Answer 22

They can all form ions with a 1+ charge.

Question 23

Group 18 (noble gases) have what in common because of their similar valence arrangements?

Answer 23

They all have filled valence shells, so they are not very reactive.

Question 24

What are isotopes?

Answer 24

Isotopes are two or more forms of an element with the same # of protons and different # of neutrons.