TASC Science 3 — Questions and Answers
Question 1: Which subatomic particle has a negative electric charge?
- Electron (Correct answer)
- Proton
- Neutron
- Nucleus
Correct answer: Electron
Electrons carry a negative charge and orbit the nucleus of an atom.
Question 2: What is the term for a substance made of two or more elements chemically combined?
- Compound (Correct answer)
- Mixture
- Solution
- Isotope
Correct answer: Compound
A compound forms when elements bond chemically in a fixed ratio.
Question 3: When water changes from a liquid to a gas, this physical change is called what?
- Evaporation (Correct answer)
- Condensation
- Freezing
- Sublimation
Correct answer: Evaporation
Evaporation is the change from liquid to gas at the surface of a liquid.
Question 4: On the periodic table, elements in the same vertical column are called a what?
- Group (Correct answer)
- Period
- Series
- Phase
Correct answer: Group
Elements in the same vertical column form a group and share similar properties.
Question 5: Which type of chemical reaction releases energy, often as heat?
- Exothermic (Correct answer)
- Endothermic
- Neutral
- Reversible
Correct answer: Exothermic
Exothermic reactions release energy, usually in the form of heat, to the surroundings.
Question 6: What does the pH scale measure in a solution?
- Acidity or basicity (Correct answer)
- Temperature
- Density
- Conductivity
Correct answer: Acidity or basicity
The pH scale measures how acidic or basic a solution is, from 0 to 14.
Question 7: In a chemical equation, the substances present before the reaction occurs are called the what?
- Reactants (Correct answer)
- Products
- Catalysts
- Solvents
Correct answer: Reactants
Reactants are the starting substances that are transformed into products.
TASC Science 3
Which subatomic particle has a negative electric charge?