Download Homework 1B1 - 3 - Uddingston Grammar School

Uddingston Grammar School
National 5 Chemistry
Atomic Structure and Bonding
Unit 1 sub-unit b.1 Homework 3
1. An element has an atomic number of 11 and a mass number of 23. The number
of electrons present in an atom of this element is?
A
B
C
D
11
12
23
34
(1)
2. Which line in the table correctly describes a neutron?
A
B
C
D
Mass
1
Negligible
1
1
Charge
-1
0
+1
0
(1)
3. Which of the following is the electron arrangement of sodium metal?
A
B
C
D
2,8,1
2,8,2
2,8,7
2,8,8
(1)
4. Isotopes of the same element have identical
A
B
C
D
nuclei
mass number
number of neutrons
number of protons
(1)
5. An atom has 26 protons, 26 electrons and 30 neutrons.
The atom has
A
B
C
D
atomic
atomic
atomic
atomic
number
number
number
number
26,
56,
30,
52,
mass number
mass number
mass number
mass number
56
30
26
56
(1)
6. The table shows the numbers of protons, electrons and neutrons in four
particles, W, X, Y and Z.
Which pair of particles are isotopes?
A
B
C
D
W and X
W and Y
X and Y
Y and Z
(1)
7. Sodium has 10 electrons.
(a) Complete the diagram to show how the electrons are arranged.
You may wish to use the data booklet to help you.
(1)
(b) Explain what holds the negatively charged electrons in place around the
nucleus.
(1)
8. The Group 7 element bromine was discovered by Balard in 1826. Bromine gets
its name from the Greek ‘bromos’ meaning stench. Bromine consists of a
mixture of two isotopes 79Br and 81Br.
(a) What is meant by the term isotope?
(b) Complete the table for
Isotope
(1)
79Br.
(1)
Number of protons
Number of neutrons
79Br
35
(c) The relative atomic mass of an element can be calculated using the
formula:
A sample of bromine contains 55% of the isotope with mass 79 and 45% of
the isotope with mass 81.
Calculate the relative atomic mass of bromine in this sample.
(2)
9. Which line in the table correctly describes an electron?
A
B
C
D
Mass
Charge
negligible
negligible
1
1
+1
–1
+1
0
(1)
10. In the manufacture of glass, other chemicals can be added to alter the
properties of the glass. The element boron can be added to glass to make
ovenproof dishes.
(a) Information about an atom of boron is given in the table below.
Particle
proton
neutron
Number
5
6
Use this information to write the nuclide notation for this atom of boron.
(1)
(b) Atoms of boron exist which have the same number of protons but a
different number of neutrons. What name can be used to describe these
different types of boron atoms?
(1)