Home / iGCSE / Coordinated Sciences / C2.7 Metallic bonding Paper 1 |IITIAN ACADEMY

CIE iGCSE Co-Ordinated Science C2.7 Metallic bonding Exam Style Questions Paper 1

CIE iGCSE Co-Ordinated Science Paper 1 - All Chapters

Question

One atom of an isotope of fluorine is represented by \( ^{15}_{9}\text{F} \).

How many neutrons does this atom have?

A. 6
B. 9
C. 10
D. 15

▶️ Answer/Explanation

In the nuclide notation \( ^{A}_{Z}\text{X} \):

  • The top number (A) is the nucleon number (mass number), which is the total number of protons and neutrons in the nucleus.
  • The bottom number (Z) is the proton number (atomic number), which is the number of protons in the nucleus.

For \( ^{15}_{9}\text{F} \):

  • Nucleon number = 15
  • Proton number = 9

The number of neutrons is found by subtracting the proton number from the nucleon number:

\(\text{Number of neutrons} = 15 – 9 = 6\)

Therefore, this atom of fluorine has 6 neutrons. Option A is correct.

✅ Answer: (A)

Question

Which row shows the particles in the nucleus of an atom of \( {}_{12}^{25}\textrm{Mg} \)?

▶️ Answer/Explanation
For \( {}_{12}^{25}\text{Mg} \): the proton number (atomic number) is 12, so the nucleus contains 12 protons; the nucleon number (mass number) is 25, so the number of neutrons \( = 25 – 12 = 13 \).
The nucleus therefore contains 12 protons and 13 neutrons (electrons are outside the nucleus and are not counted here).
✅ Answer: (B)

Question

The nucleus of an isotope of gold contains 79 protons and 118 neutrons. The symbol for gold is Au.
What is the nuclide symbol for this isotope?

A. \( ^{79}_{118}\text{Au} \)
B. \( ^{79}_{197}\text{Au} \)
C. \( ^{118}_{79}\text{Au} \)
D. \( ^{197}_{79}\text{Au} \)

▶️ Answer/Explanation
The proton number (bottom number) is the number of protons, which is 79 for gold.
The nucleon number (top number) is the total number of protons and neutrons: \( 79 + 118 = 197 \).
So the correct nuclide symbol is \( ^{197}_{79}\text{Au} \), with 197 on top and 79 on the bottom.
✅ Answer: (D)

Question

Which row describes an atom that has the nucleon number 24?

▶️ Answer/Explanation
The nucleon number (mass number) equals the sum of protons and neutrons: \( A = Z + N \).
For a neutral atom, the number of electrons always equals the number of protons.
Row B (12 protons, 12 neutrons, 12 electrons) gives \( 12+12 = 24 \), matching a neutral magnesium atom.
✅ Answer: (B)

Question

X and Y are isotopes of the same element.

Which statement about X and Y is correct?

A. They have the same nucleon number but different numbers of protons.
B. They have the same number of neutrons but different numbers of electrons.
C. They have the same atomic number but different numbers of electrons.
D. They have the same number of protons but different numbers of neutrons.

▶️ Answer/Explanation
Isotopes are atoms of the same element with the same number of protons (same atomic number).
Because they are neutral atoms of the same element, they also have the same number of electrons.
Isotopes differ only in the number of neutrons, and therefore in nucleon (mass) number.
✅ Answer: (D)
More CIE iGCSE Co-Ordinated Science Paper 1 Questions..
Scroll to Top