CIE iGCSE Co-Ordinated Science C2.2 Atomic structure and the Periodic Table Exam Style Questions Paper 1
Question
The structures of some substances are shown.
Which row shows the total number of different elements and the total number of atoms in the three structures?
| Option | Total Number of Different Elements | Total Number of Atoms |
|---|---|---|
| A | 3 | 9 |
| B | 3 | 17 |
| C | 7 | 9 |
| D | 7 | 17 |
▶️Answer/Explanation
Answer: B
Explanation: The three substances contain 3 different elements (H, C, O) and a total of 17 atoms (2 in H₂O, 9 in C₂H₅OH, and 6 in CH₄).
Question
The protons, neutrons, and electrons in a particle are shown.
Which symbol represents this particle?
A. F
B. F⁻
C. Ne
D. Ne⁺
▶️Answer/Explanation
Answer: B. F⁻
Explanation: The particle has 9 protons (fluorine), 10 neutrons, and 10 electrons. Since it has one more electron than protons, it is a fluoride ion (F⁻).
Question
Which row does not link a general physical property to the type of element?
▶️Answer/Explanation
Ans : C
Question
An atom of an element contains 9 protons, 10 neutrons and 9 electrons.
What is the nucleon number (mass number) of this element?
(A) 9
(B) 10
(C) 19
(D) 28
▶️Answer/Explanation
Ans: C
Question
An atom of fluorine is represented by $\frac{19}{9}F$.
How many electrons does this atom contain?
(A) 9
(B) 10
(C) 19
(D) 28
▶️Answer/Explanation
Ans : A
Question
An atom of osmium is represented by 76190Os.
How many neutrons are in this atom?
A 76 B 114 C 190 D 266
▶️Answer/Explanation
Ans : B
Question
Which row describes an atom that has the nucleon number 24?
▶️Answer/Explanation
Ans : B
Question
The element phosphorus burns in air, as shown.
4P + 5O2 → P4O10
What does the formula P4O10 show?
(A) a mixture of atoms of two elements
(B) a mixture of molecules of two elements
(C) a molecule of a compound
(D) an atom of a compound
▶️Answer/Explanation
Ans : C
Question
The nucleon number of a hydrogen atom is 1.
What is present inside the nucleus of this atom?
(A) one proton and one electron
(B) one proton and one neutron
(C) one proton only
(D) one neutron only
▶️Answer/Explanation
Ans : C
Question
What do the chemical symbols N2 and Ni represent?
▶️Answer/Explanation
Ans : D
Question
Which row shows the particles in the nucleus of an atom of \( _{12}^{25}\textrm{Mg}\)?
▶Answer/Explanation
Ans : B
Question
Which statement about atom is correct?
(A) All atoms contain equal numbers of neutrons and protons.
(B) All atoms of the same element have the same number of neutrons.
(C) The Periodic Table lists atoms in order of increasing mass number.
(D) The smallest unit of an element is an atom.
▶️Answer/Explanation
Ans: D
Question
Atoms are the smallest parts of ……1…….
When atoms of the same type chemically join together, a ……2…… is formed.
When different types of atom chemically join together, they form ……3…….
Which words complete gaps 1, 2 and 3?
A. elements, molecule, compounds
B. elements, molecule, mixtures
C. molecules, compound, mixtures
D. molecules, mixture, compounds
▶️Answer/Explanation
Answer: A. elements, molecule, compounds
Explanation: Atoms are the smallest parts of elements. When atoms of the same type join together, they form molecules. When different types of atoms join together, they form compounds.
Question
Potassium is in Group I of the Periodic Table.
What is a property of potassium?
A. It does not react with water.
B. It is a liquid.
C. It is a non-metal.
D. It is a soft metal.
▶️Answer/Explanation
Answer: D. It is a soft metal.
Explanation: Potassium is a Group I alkali metal, which is known for being soft and highly reactive with water. It is not a liquid at room temperature, and it is a metal, not a non-metal.
Question
Which statement about atoms and molecules is correct?
A. All molecules are gases at room temperature and pressure.
B. An atom is the smallest part of an element.
C. Atoms of the same element all have the same mass.
D. Molecules always contain atoms of more than one element.
▶️Answer/Explanation
Answer: B. An atom is the smallest part of an element.
Explanation: An atom is the smallest unit of an element that retains its chemical properties. Molecules can be made up of atoms of the same or different elements, and not all molecules are gases at room temperature.
Question
Which row shows the particles in the nucleus of an atom of 2512Mg?
| protons | neutrons | |
|---|---|---|
| A | 12 | 12 |
| B | 12 | 13 |
| C | 13 | 12 |
| D | 13 | 13 |
▶️Answer/Explanation
Answer: B
Explanation: The atomic number (proton number) of magnesium (Mg) is 12, so it has 12 protons. The mass number is 25, which is the sum of protons and neutrons. Therefore, the number of neutrons is 25 – 12 = 13.
Question
Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown.
What is the formula of hydrogen peroxide?
A HO
B H2O2
C (OH)2
D 2OH
▶️Answer/Explanation
Answer: B
Explanation: The chemical formula for hydrogen peroxide is H2O2.