BMAT Knowledge 4 — Questions and Answers
Question 1: A solution has a pH of 3. What is its hydrogen ion concentration [H⁺]?
- 3 mol/L
- 10⁻³ mol/L (Correct answer)
- 10³ mol/L
- 0.3 mol/L
Correct answer: 10⁻³ mol/L
pH = −log[H⁺], so [H⁺] = 10^(−pH) = 10⁻³ mol/L.
Question 2: What type of electromagnetic radiation has the shortest wavelength?
- Radio waves
- Visible light
- Ultraviolet
- Gamma rays (Correct answer)
Correct answer: Gamma rays
Gamma rays have the shortest wavelengths (below 10⁻¹¹ m) and highest frequencies in the electromagnetic spectrum.
Question 3: During meiosis, crossing over between non-sister chromatids occurs during which phase?
- Metaphase I
- Prophase I (Correct answer)
- Anaphase II
- Telophase I
Correct answer: Prophase I
Crossing over occurs during Prophase I when homologous chromosomes pair up to form bivalents.
Question 4: A rectangular block has dimensions 2 cm × 3 cm × 5 cm and mass 90 g. What is its density?
- 0.3 g/cm³
- 3 g/cm³ (Correct answer)
- 9 g/cm³
- 15 g/cm³
Correct answer: 3 g/cm³
Volume = 2×3×5 = 30 cm³; density = 90/30 = 3 g/cm³.
Question 5: Which type of chemical bond involves the sharing of electron pairs between atoms?
- Ionic bond
- Covalent bond (Correct answer)
- Metallic bond
- Hydrogen bond
Correct answer: Covalent bond
Covalent bonds form when atoms share pairs of electrons, typically between two non-metals.
Question 6: The transpiration stream in plants moves water from:
- Leaves to roots via phloem
- Roots to leaves via xylem (Correct answer)
- Roots to leaves via phloem
- Leaves to roots via xylem
Correct answer: Roots to leaves via xylem
Water is absorbed by roots, transported upward through xylem vessels, and lost through stomata in leaves.
Question 7: If the half-life of a radioactive isotope is 10 years, what fraction of the original sample remains after 30 years?
- 1/2
- 1/4
- 1/8 (Correct answer)
- 1/16
Correct answer: 1/8
30 years = 3 half-lives; after each half-life the amount halves: (1/2)³ = 1/8 remains.
BMAT Knowledge 4
A solution has a pH of 3.
What is its hydrogen ion concentration [H⁺]?