National 4 and National 5 Chemistry

National 4 & 5 Chemistry / Atomic Structure Practice Examples

NATIONAL 4 AND NATIONAL 5 CHEMISTRY

Unit 1: Chemical Changes and Structure

(B) ATOMIC STRUCTURE & BONDING RELATED TO PROPERTIES

NATIONAL 4 AND NATIONAL 5 CHEMISTRY

Unit 1: Chemical Changes and Structure

ATOMIC STRUCTURE

PRACTICE EXAMPLES BOOKLET

N4/5

/ HISTORY OF THE ATOM /

N4/5

Chemistry: Development of the Atomic Theory (research task)

Directions: write the numbers 1-22 in a list in your jotter and next to each number use the correct word from the word bank.

Word List

atom mass number Dalton proton

atomic number multiple proportions electron quantum

Bohr neutron definite proportions Proust

Chadwick nucleus subatomic particle isotopes

Planck energy level Rutherford Lavoisier

Thomson conservation of matter

More than 2000 years ago, Greek philosophers proposed the existence of very small, indivisible particles, each of which was called an __(1)__. The theory that such particles existed was supported, much later, by __(2)__, who proposed, in his law of __(3)__, that matter cannot be created or destroyed. Then __(4)__ proposed, in his law of __(5)__, that the ratio of the masses of elements in any given compound is always the same. The law of __(6)__, proposed soon after, states that the masses of one element that combine with a fixed mass of another element in different compounds are in simple, whole-number ratios. An atomic theory based on these laws was developed by __(7)__.

It was later proposed that the atom was not indivisible, but is made up of smaller particles, each of which is called an __(8)__. These particles include the negatively-charged __(9)__, discovered by __(10)__; the positively-charged __(11)__; and the uncharged __(12)__, discovered by __(13)__. The latter two particles are present in the __(14)__, or center, of the atom, which was discovered by __(15)__ in his gold foil experiment.

The number of positively-charged particles in an atom is called its __(16)__. The sum of the positively-charged particles and the uncharged particles is called the __(17)__ of the atom. Atoms that have the same number of positively-charged particles but different numbers of uncharged particles are called __(18)__.

The Danish physicist __(19)__ proposed a model of the atom in which the electrons orbit the nucleus without losing energy. He called each possible orbit an __(20)__. He based his theory, to some extent, on the work of __(21)__, who proposed that light is made up of units of energy of a definite amount, each of which is called a(n) __(22)__ of energy.

N4

ATOMS AND ATOMIC NUMBER

N4

Atomic
Number / Element Name / Element
Symbol / Charge in nucleus / Number of protons / Number of electrons
12 / 12
34 / 34
bromine
hydrogen
O
16+
23
92
Ar
rubidium
47+
82
50
Au
13 / 13
silicon
53+
He
74
chlorine
Po

N5

ATOM NUMBERS 1

N5

Atom Symbol / Atomic Number / Mass Number / Number of Protons / Number of Electrons / Number of Neutrons
Li
Na
O
K
Cu
Au
Al
Ni
I
Hg
C

N5

ATOM NUMBERS 2

N5

Atom Symbol / Atomic Number / Mass Number / Number of Protons / Number of Electrons / Number of Neutrons
Be / 4 / 9
Mg
Cl / 17 / 20
Br / 35 / 46
S / 16 / 16
Zr
Cu / 64 / 35
Cr / 24 / 52
Cf / 251
Cs
Pb / 125

N5

MASS NUMBERS AND ISOTOPES

N5

Read the following information about a mass spectrometer and the detection of isotopes and answer the questions on the following page.

Q1) Using the example calculation copy and complete the table to calculate the relative atomic mass of the five samples from the abundance of their respective isotopes.

N5

/ ELECTRON ARRANGEMENTS
OF ATOMS AND IONS /

In your jotter, write the headings from the table below. Using the Periodic Table with the electron arrangements of atoms in the chemistry data booklet, complete the table below.

Element / Symbol / Electron Arrangement of Atom / Ion Symbol / Electron Arrangement of Ion
lithium
oxygen
magnesium
sulphur
nitrogen
calcium
aluminium
potassium
bromine

N5

IONS, ATOMS AND NUMBERS

PART 1 – IONS

Ion Symbol / Atomic Number / Mass Number / No. of Protons / No. of Neutrons / No. of Electrons / Electron Arrangement
Cl-
Na+
P3-
Ca2+
Li+ / 3 / 4 / 2
K+ / 40 / 19 / 2, 8, 8
S2- / 16 / 17 / 18
H+ / 1 / 2 / 0
Ag+ / 108 / 47 / 61 / 2, 8, 18, 18
Pb4+ / 82 / 125 / 2, 8, 18, 32, 18

IONS, ATOMS AND NUMBERS

PART 2 – ATOMS

Atom Symbol / Atomic Number / Mass Number / No. of Protons / No. of Neutrons / No. of Electrons / Electron Arrangement
Li
He
Si
C
Na / 23 / 11
Mg / 12 / 12
Be / 4 / 5
Kr / 48 / 2, 8, 18, 8
F / 9 / 19
Pb / 207 / 2, 8, 18, 32, 18, 4

IONS, ATOMS AND NUMBERS

PART 3 – ATOMS AND IONS

REMEMBER In an ion the number of electrons is NOT EQUAL to the number of protons.

Atom / Ion Symbol / Atomic Number / Mass Number / No. of Protons / No. of Neutrons / No. of Electrons / Electron Arrangement
H / 3
3 / 7 / 3
K+
Cl / 20
7 / 15 / 7
53 / 76 / 2, 8, 18, 18 , 8
26 / 56 / 26 / 30 / 23 / 2, 8, 13
79 / 118 / 77 / 2, 8, 18, 32, 17
22 / 26 / 2, 8, 9

NATIONAL 4 AND NATIONAL 5 CHEMISTRY

Unit 1: Chemical Changes and Structure

BONDING, STRUCTURES & PROPERTIES

PRACTICE EXAMPLES BOOKLET

/ CLASSIFICATION 1 /

Compound or Element?

In your jotter, write the headings from the table below.

Write the formulae of each substance then classify each as either COMPOUND or ELEMENT. Also classify the ELEMENTS and METAL or NON-METAL.

Substance / Formula / Classification
(Compound or Element?) / Type of Element?
(Metal or Non-metal)
Oxygen
Carbon dioxide
Potassium sulphide
Aluminium
Phosphorus
Chromium
Silicon oxide
Argon
Gold
Nitrogen iodide
Lithium oxide
Tungsten
Chlorine
Carbon monoxide
Calcium bromide
Boron oxide
Bromine

/ CLASSIFICATION 2 /

Type of Bonding?

In your jotter, write the headings from the table below.

Write the formulae of each substance then classify each by the type of bonding which holds their atoms together i.e. METALLIC, IONIC or COVALENT.

Substance / Formula / Bonding in Substance
(Metallic, ionic or covalent?)
Copper
Magnesium chloride
Carbon fluoride
Phosphorus pentachloride
Magnesium chloride
Nitrogen dioxide
Octane / C8H18
Potassium
Aluminium sulphide
Trichloromethane / CHCl3
Calcium oxide
Silicon dioxide
Gold
Ethanol / C2H5OH
Sodium iodide
Arsenic
Glucose / C6H12O6

/ FORMULAE WITH STATE SYMBOLS /

In your jotter, write the headings from the table below.

Write the missing formula with state symbol OR name the substance including its state.

Substance / Formula
Liquid oxygen /
Solid carbon dioxide (dry ice) /
KCl(aq) /
Al(s) /
Ice (frozen water) /
Nitrogen gas
Li2O(l)
He(g)
Sodium bromide solution
I2(s) /

/ ION FORMULAE /

In your jotter, write the headings from the table below. The first two rows have been done for you to show you what to do.

Starting with potassium complete the table.

Element / Symbol / Element Type
(metal / non-metal) / Valency / Ion Formula / Number of electrons lost or gained by atom?
magnesium / Mg / metal / 2 / Mg2+ / 2 electrons lost
chlorine / Cl / non-metal / 1 / Cl / 1 electron gained
potassium
oxygen
bromine
aluminium
calcium
phosphorus
strontium
nitrogen
rubidium
barium
fluorine
sulphur
iodine
caesium
selenium

/ COVALENT BONDING DIAGRAMS /

Collect the cut out sheet called COVALENT BONDING DIAGRAMS.

Complete the diagrams of the covalent bonding and draw the full structural formula of each substance under each diagram.

hydrogen, H2 / chlorine, Cl2 / nitrogen, N2
hydrogen fluoride, HF / hydrogen sulphide, H2S / carbon hydride, CH4
silicon chloride, SiCl4 / nitrogen hydride, NH3 / carbon dioxide, CO2
Page 1 of 18