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Essential Chemistry for IGCSE - Atoms, Elements And Compounds (Section 3)

1
If an atom has 10 protons and 12 neutrons, what is its mass number?
Answer
(D)
22
2
Which of the following is a characteristic property that can be used to identify non-metals?
Answer
(C)
Brittle
3
What is the basic building block of matter?
Answer
(C)
Atom
4
In a covalent bond, what is shared between atoms?
Answer
(C)
Electrons
5
Which of the following is a chemical bond?
Answer
(B)
A molecule of oxygen gas (O2)
6
Which property of metals is related to their ability to be drawn into wires?
Answer
(C)
Ductility
7
What is the name for an atom that has gained or lost electrons?
Answer
(B)
Ion
8
Which of the following statements correctly describes a compound?
Answer
(B)
A substance made of two or more elements chemically combined in a fixed ratio.
9
Which of the following is a characteristic of a mixture?
Answer
(C)
The components can be separated by physical means.
10
Which is NOT a property of a metal?
Answer
(D)
Brittle
11
What is the charge of a proton?
Answer
(A)
+1
12
What is the key difference between a compound and a mixture?
Answer
(C)
Compounds involve chemical bonds, while mixtures do not.
13
What is the formula to calculate the number of neutrons in an atom?
Answer
(B)
Number of neutrons = mass number - proton number
14
Which of the following elements would most likely form a covalent bond?
Answer
(B)
Chlorine
15
Which of the following is an example of an isotope?
Answer
(B)
Two atoms of the same element with different numbers of neutrons.
16
In the context of an atom, what are 'shells'?
Answer
(B)
The regions around the nucleus where electrons are likely to be found.
17
Which of the following is a characteristic of a mixture?
Answer
B
C
18
Which of the following determines an element's identity?
Answer
(C)
Number of protons
19
What type of particles make up a chemical bond?
Answer
(C)
Electrons
20
What is the difference between elements and compounds?
Answer
(B)
Elements are made of only one type of atom; compounds are made of different elements bonded.
21
Which statement best describes a chemical compound?
Answer
(C)
A substance with a fixed composition formed by chemical bonds.
22
Which of the following is a property of metals?
Answer
(C)
High melting points
23
What type of radiation is used in medical imaging like X-rays?
Answer
(C)
Gamma radiation
24
What does a chemical bond involve?
Answer
(B)
Sharing of electrons
25
Which of the following is considered a physical property?
Answer
(C)
Density
26
What is a covalent bond?
Answer
(B)
A bond formed by the sharing of electrons.
27
Which of the following statements are TRUE about the differences between metals and non-metals?
Answer
A
B
28
Which of the following are used in medical treatments?
Answer
(A)
Isotopes
29
Which properties can be used to classify a substance as a metal or a non-metal?
Answer
A
B
D
30
Which of the following is found in the nucleus of an atom?
Answer
(B)
Protons and neutrons
31
How does the number of protons in an atom relate to its atomic number?
Answer
(B)
The atomic number is the number of protons in the nucleus.
32
How is the electronic structure of an atom arranged?
Answer
(B)
In layers surrounding the nucleus, called shells or energy levels.
33
What is the main function of using radioactive isotopes in medicine?
Answer
(B)
To diagnose and treat diseases.
34
Which of the following are examples of elements?
Answer
B
C
35
What happens during radioactive decay?
Answer
(A)
The nucleus of an atom becomes more stable by emitting particles or energy.
36
What is the term used for atoms that have gained or lost electrons?
Answer
(B)
Ions
37
What kind of decay is represented by radioactive atoms?
Answer
(C)
Radioactive isotopes spontaneously decay.
38
Which of the following properties can distinguish a metal from a non-metal?
Answer
A
B
C
39
What is the relationship between the atomic number and the number of electrons in a neutral atom?
Answer
(C)
Atomic number is equal to the number of electrons.
40
What is the maximum number of electrons that the first electron shell can hold?
Answer
(A)
2
41
How can you calculate the number of neutrons in an atom?
Answer
(B)
Mass Number - Atomic Number
42
What makes a substance radioactive?
Answer
(B)
The element is unstable and decays spontaneously
43
What is an isotope?
Answer
(C)
Atoms of the same element with different numbers of neutrons
44
What makes a metal 'malleable'?
Answer
(C)
Ability to be hammered into shape.
45
Which of the following is NOT found in the atom's nucleus?
Answer
(C)
Electrons
46
What is a compound?
Answer
(C)
A substance formed when two or more elements are chemically bonded.
47
Which of the following are properties of a metallic element?
Answer
B
C
48
What is the purpose of neutrons in an atom?
Answer
(B)
To provide stability to the nucleus
49
Which of the following describes the nature of a mixture?
Answer
B
D
50
The outermost electrons in an atom are called:
Answer
(B)
Valence electrons