Science Quiz Practice: What Do You Know?

Water is matter because it has mass and occupies space. In contrast, sound and light are forms of energy and do not have volume or mass.

Sunlight provides the energy required for photosynthesis, which is essential for plant growth. While water, soil minerals, and oxygen are also important, sunlight is the key energy source.

The cell is the smallest unit that carries out all the functions of life. Atoms and molecules are the building blocks within cells, while organs are made up of multiple cells working together.

Gravity is the force that pulls objects toward the center of the Earth. Friction, magnetism, and inertia represent different forces or properties and do not cause objects to fall.

Wind energy is renewable because it relies on the natural and continuously replenished movement of air. Coal, oil, and natural gas are fossil fuels that cannot be replenished on a human time scale.

The outer core of the Earth is liquid and is primarily composed of molten iron and nickel. Meanwhile, the inner core is solid, and the mantle and crust are composed of rock.

Evaporation is the process in which water molecules gain enough energy to transition from a liquid state to a gaseous state. The other processes involve water changing form in different ways, but only evaporation changes liquid water into vapor directly.

Nitrogen makes up about 78% of the Earth's atmosphere, making it the most abundant gas. Although oxygen and carbon dioxide are essential for processes like respiration and climate regulation, they are not as prevalent.

A seesaw operates as a lever, which is a simple machine that uses a fulcrum to balance forces. The other options represent different types of simple machines that do not accurately describe a seesaw.

Mitochondria are responsible for producing ATP, the energy currency of the cell, which is why they are termed the powerhouse of the cell. Other organelles, like the nucleus or ribosome, perform different specialized functions.

Day and night occur as a result of the Earth's rotation on its axis, which alternately exposes different parts of the Earth to the sun. Although Earth's revolution and tilt influence seasons, they do not create the daily cycle of daylight and darkness.

Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to produce food and oxygen. The other options describe processes that either use up energy or occur in different organisms.

Friction is the resistive force that acts when two surfaces slide against each other, slowing down movement. Gravity, magnetism, and inertia have different roles and do not primarily serve as a resistance to motion.

Hydrogen is the most abundant element in the universe and plays a critical role in the formation of stars and galaxies. The other elements, while common on Earth, are far less abundant on a cosmic scale.

Chemical energy is stored in the molecular bonds of food and is released during digestion. Although thermal, kinetic, and potential energies exist, they are not specifically associated with food storage.

Developing a testable prediction is the hypothesis stage of the scientific method. This step lays the groundwork for experimentation and data analysis by providing a focused question to investigate.

The law of conservation of mass states that mass remains constant before and after a chemical reaction. The other options conflict with this fundamental principle of science.

A scientific law describes an observable phenomenon, whereas a theory provides an explanatory framework for why that phenomenon occurs. This distinction is vital in understanding how scientific knowledge is structured and validated.

A roller coaster converting potential energy into kinetic energy is a clear example of energy transformation. This process demonstrates how stored energy can be converted to motion, unlike the other scenarios that do not involve a discernible conversion.

A control group establishes a baseline by not receiving the experimental treatment, allowing scientists to isolate the effects of the variable being tested. This comparison is essential for accurate interpretation of the results.