TEAS Science: Chemistry and Physical Science 2 — Questions and Answers
Question 1: Which subatomic particle determines the identity of an element?
- Proton (Correct answer)
- Neutron
- Electron
- Positron
Correct answer: Proton
The number of protons (atomic number) defines which element an atom is.
Question 2: What is the pH of a neutral solution at 25°C?
- 0
- 7 (Correct answer)
- 10
- 14
Correct answer: 7
A neutral solution has a pH of 7, where hydrogen and hydroxide ion concentrations are equal.
Question 3: Which type of 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 electron pairs.
Question 4: A change from a liquid directly to a gas is called what?
- Condensation
- Sublimation
- Vaporization (Correct answer)
- Deposition
Correct answer: Vaporization
Vaporization is the phase change from liquid to gas.
Question 5: Which law states that energy cannot be created or destroyed?
- Law of conservation of energy (Correct answer)
- Newton's second law
- Boyle's law
- Ohm's law
Correct answer: Law of conservation of energy
The law of conservation of energy says energy only transforms between forms.
Question 6: What does the atomic mass of an element primarily represent?
- Protons only
- Electrons only
- Protons plus neutrons (Correct answer)
- Neutrons minus protons
Correct answer: Protons plus neutrons
Atomic mass is approximately the sum of protons and neutrons in the nucleus.
Question 7: Which of these is a chemical change rather than a physical change?
- Melting ice
- Boiling water
- Rusting iron (Correct answer)
- Crushing a can
Correct answer: Rusting iron
Rusting forms a new substance (iron oxide), making it a chemical change.
TEAS Science: Chemistry and Physical Science 2
Which subatomic particle determines the identity of an element?