Practise Questions: C-2: Atoms,Elements and Compounds
1 Particle Electrons Protons Neutrons
A 12 12 12
B 12 12 14
C 10 12 12
D 10 8 8
E 9 9 10
The table above describes some particles.
a Which three particles are neutral atoms?
b Which particle is a negative ion? What is the charge on this ion?
c Which particle is a positive ion? What is the charge on this ion?
d Which two particles are isotopes?
e Use the table on periodic table to identify A to E.
2 The following statements are about the particles that make up the atom.
For each statement write:
p if it describes the proton
e if it describes the electron
n if it describes the neutron
A the positively-charged particle
B found with the proton, in the nucleus
C the particle that can occur in different numbers, in atoms of the
same element
D held in shells around the nucleus
E the negatively-charged particle
F the particle with negligible mass
G the number of these particles is found by subtracting the proton
number from the nucleon number
H the particle with no charge
I the particle with the same mass as a neutron
J the particle that dictates the position of the element in the
Periodic Table
3 The atoms of an element can be represented by a set of three letters,
y
as shown on the right. z X
a What does this letter stand for?
i X ii y iii z
b How many neutrons are there in these atoms?
47 29 10 92
i 107 Ag ii 63 Cu iii 11H iv 20Ne v 238U
c Bromine atoms have 45 neutrons and 35 protons. Describe them using
the method in b.
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4 For each of the six elements aluminium (Al), boron (B), nitrogen (N),
oxygen (O), phosphorus (P), and sulfur (S), write down:
a i which period of the Periodic Table it belongs to
ii its group number in the Periodic Table
iii its proton number
iv the number of electrons in its atoms
v its electronic configuration
vi the number of outer electrons in its atoms
b The outer electrons are also called the _____ electrons. What is the
missing word? (7 letters!)
c Which of the above elements would you expect to have similar
properties? Why?
5 Boron has two types of atom, shown below.
proton
neutron
electron
atom A atom B
a What is different about these two atoms?
b What name is given to atoms like these?
c Describe each atom in shorthand form, as in 3.
d What is the nucleon number of atom A?
e Is atom B heavier, or lighter, than atom A?
f i Give the electronic configuration for A and B.
ii Comment on your answer for i.
6 The two metals sodium (proton number 11) and magnesium (proton
number 12) are found next to each other in the Periodic Table.
a Say whether this is the same, or different, for their atoms:
i the number of electron shells
ii the number of outer (valency) electrons
The relative atomic mass of sodium is 23.0.
The relative atomic mass of magnesium is 24.3.
b Which of the two elements may exist naturally as a single isotope?
Explain your answer.
7 Strontium, proton number 38, is in the fifth period of the Periodic Table.
It belongs to Group II.
Copy and complete the following.
An atom of strontium has:
a …………….. electrons
b ……………. shells of electrons
c …………….. electrons in its outer shell
8 This diagram represents the electronic arrangement in an atom of an element.
a i Give the electron distribution for the atom.
ii What is special about this arrangement?
b Which group of the Periodic Table does the element belong to?
c Name another element with the same number
of outer-shell electrons in its atoms.
9 Gallium exists naturally as a mixture of two non-radioactive isotopes,
gallium-69 and gallium-71. The proton number of gallium is 31.
a i How many neutrons are there in gallium-69?
ii How many neutrons are there in gallium-71?
Gallium also has a radioactive isotope, gallium-67.
As gallium-67 decays, it gives out rays called gamma rays.
b How does the radioactive isotope differ from
the non-radioactive isotope?
c Give two uses, one medical and one non-medical, for radioisotopes.
10 Read this passage about metals.
Elements are divided into metals and non-metals. All metals are electrical
conductors. Many of them have a high density and they are usually ductile
and malleable. All these properties influence the way the metals are used.
Some metals are sonorous and this leads to special uses for them.
a Explain the underlined terms.
b Copper is ductile. How is this property useful in everyday life?
c Aluminium is hammered and bent to make large structures for use in
ships and planes. What property allows it to be shaped like this?
d Name one metal that has a low density.
e Some metals are cast into bells. What property must the chosen
metals have?
f Give the missing word: Metals are good conductors of .......... and
electricity.
g Choose another physical property of metals, and give two examples
of how it is useful.
h Phosphorus is a solid non-metal at room temperature. What other
physical properties would you expect it to have?
i Explain how the chemical properties of metals and non-metals can
be used to tell them apart.
