What is the plum pudding model of the atom?
An atom is a ball of positive charge with negative electrons embedded in it
An atom is a ball of negative charge with positive electrons embedded in it
An atom is a ball of positive charge with negative neutrons embedded in it
Which scientist found evidence for the existence of neutrons?
James Chadwick
Niels Bohr
Ernest Rutherford
What is the radius of a typical atom?
1 × 10-6 m
1 × 10-10 m
1 × 10-14 m
What is the relative mass and charge of a neutron?
Mass = 1 and charge = -1
Mass = 0 and charge = +1
Mass = 1 and charge = 0
An atom has 13 protons and 14 neutrons. What is its mass number?
14
13
27
An atom has an atomic number of 9 and a mass number of 19. What are its numbers of protons, neutrons and electrons?
Protons = 10, neutrons = 19, electrons = 10
Protons = 9, neutrons = 10, electrons = 9
Protons = 19, neutrons = 10, electrons = 19
What are isotopes?
Atoms of the same element with different numbers of neutrons
Atoms of the same element with different numbers of protons
Atoms of the same element with different numbers of electrons
Four atoms have the numbers of protons and neutrons given below. Which two atoms are isotopes of the same element?
W: 8 protons and 8 neutrons
X: 8 protons and 10 neutrons
Y: 10 protons and 8 neutrons
Z: 9 protons and 10 neutrons
X and Y
W and X
X and Z
What is the best definition of the relative atomic mass of an element?
The number of protons in its atoms
The total number of protons and neutrons in its atoms
The average mass of its atoms compared to one-twelfth of the mass of a carbon-12 atom
A sample of naturally occurring neon is 91% neon-20 and 9% neon-22. What is its relative atomic mass?
21
21.8
20.2