Science Flashcards

A student measures the pH of a solution and gets a value of 3. The solution is:

Answer: Acidic

A pH below 7 indicates an acidic solution; pH 3 is strongly acidic, while pH 7 is neutral and above 7 is basic.

Which process separates homologous chromosomes during meiosis?

Answer: Meiosis I

During Meiosis I, homologous chromosome pairs separate from each other, halving the chromosome number.

What causes the seasons on Earth?

Answer: The tilt of Earth's axis as it orbits the Sun

Earth's 23.5° axial tilt causes different hemispheres to receive more direct sunlight at different points in Earth's orbit, creating seasons.

Which best explains why metals are good conductors of electricity?

Answer: Metals contain free-moving electrons in their structure

Metals have a 'sea' of delocalized (free) electrons that can move easily through the material, allowing electrical current to flow.

In a food chain, which organism always occupies the first trophic level?

Answer: Producer

Producers (plants and other photosynthetic organisms) always occupy the first trophic level because they capture energy from the Sun.

What happens to the atomic number of an element when it undergoes beta decay?

Answer: It increases by 1

In beta decay, a neutron converts into a proton and an electron (beta particle); the extra proton increases the atomic number by 1.

Which of the following correctly describes the difference between speed and velocity?

Answer: Velocity includes direction; speed does not

Velocity is a vector quantity that includes both magnitude (speed) and direction, while speed is a scalar with magnitude only.