Welcome to your Grade 9 Chemistry chapter 3
After carefully reading the following 30 questions, choose the correct answer.
1.
From which Greek word is the term ‘atom’ derived?
2.
What does the Greek word ‘a-tomos’ mean?
3.
Who proposed the atomic theory of matter on a firm scientific basis in 1808?
4.
Which law is also known as the ‘Law of Indestructibility of Matter’?
5.
What states that the amount of matter in a system closed to transfer stays unchanged?
6.
Which law states that compounds are formed from elements in a ratio of small whole numbers?
7.
What is the charge of a neutron?
8.
Which subatomic particle was discovered by bombarding beryllium with alpha particles?
9.
Who discovered the neutron?
10.
What do all atoms of a specific element have in common?
11.
Atoms with the same number of protons but different numbers of neutrons are called:
12.
What is the atomic number (Z) of an atom?
13.
What constitutes the mass number (A) of an atom?
14.
Which subatomic particle has a relative charge of -1?
15.
The process where an unstable nucleus breaks down to a more stable form is called:
16.
Which isotope of carbon is known as a radioisotope?
17.
What is the relative charge of a proton?
18.
What unit is commonly used to express the mass of an atom?
19.
Cathode rays are composed of which subatomic particles?
20.
Which experiment eventually led to the conclusion that electrons are distributed in a large space around the nucleus?
21.
What is the atomic number of an atom with 6 protons?
22.
How many neutrons are in an atom of Carbon-14 (Atomic number 6)?
23.
Which subatomic particles account for almost all the mass of an atom?
24.
Which of the following is true about cathode rays?
25.
Who determined the magnitude of the charge of an electron using the oil droplet experiment?
26.
An atom with 2 protons is always an atom of:
27.
What causes the different glows seen in a discharge tube when cathode rays pass through gases?
28.
Which subatomic particle is neither attracted to nor repelled from objects?
29.
How many protons does an atom of Beryllium have?
30.
What is the relative mass of an electron compared to a proton?
