Physical Science Flashcards

Front

What is the term for the speed when the force of gravity is balanced by the air resistance?

Back

terminal velocity

Answer explanation

The term for the speed at which the force of gravity is balanced by air resistance is called terminal velocity. At this point, an object falls at a constant speed without accelerating.

Front

When is kinetic energy greatest for a falling object?

Back

Just before it hits the ground.

Answer explanation

Kinetic energy is greatest just before the object hits the ground because it has converted most of its potential energy into kinetic energy during the fall, reaching maximum speed at that point.

Front

Two atoms with the same number of protons must be the same element.

Back

True

Answer explanation

True. Atoms are defined as the same element if they have the same number of protons, which determines their atomic number. Therefore, two atoms with the same number of protons must indeed be the same element.

Front

Why does a straw sitting in a glass of water look "broken"?

Back

refraction

Answer explanation

A straw in water appears 'broken' due to refraction, which is the bending of light as it passes from air into water. This change in speed causes the light to change direction, making the straw look misaligned.

Front

Nitrogen makes up about how much of the air around us?

Back

78%

Answer explanation

Nitrogen constitutes about 78% of the Earth's atmosphere, making it the most abundant gas in the air we breathe. The other options, 28% and 58%, are incorrect.

Front

Which type of atomic bond involves the sharing of electrons?

Back

covalent

Answer explanation

Covalent bonds involve the sharing of electrons between atoms, allowing them to achieve stability. In contrast, ionic bonds involve the transfer of electrons. Therefore, the correct answer is covalent.

Front

Heat always flows from warm to cold.

Back

True

Answer explanation

The statement is true because heat naturally flows from areas of higher temperature to areas of lower temperature, following the second law of thermodynamics.

Front

On which side of a chemical equation are the reactants found?

Back

left

Answer explanation

In a chemical equation, the reactants are always found on the left side. The products, which are the result of the reaction, are located on the right side. Therefore, the correct answer is 'left'.

Front

Which law is shown by a balanced chemical equation?

Back

Law of Conservation of Matter (Mass)

Answer explanation

A balanced chemical equation demonstrates the Law of Conservation of Matter (Mass), which states that matter cannot be created or destroyed in a chemical reaction. The number of atoms remains constant before and after the reaction.

Front

What is the name for energy of motion?

Back

Kinetic

Answer explanation

The energy of motion is called kinetic energy. It is the energy that an object possesses due to its movement, distinguishing it from potential energy, which is stored energy based on an object's position.