6th Grade Science Practice Quiz

The Sun is the main source of energy that drives weather, climate, and life on Earth. Its energy supports processes such as photosynthesis and helps maintain the planet's temperature.

Solids have a definite shape and volume due to the close packing of their particles. The particles vibrate in place, which maintains the structure without taking on a new shape.

A thermometer is designed specifically to measure temperature using the expansion and contraction of substances. It is a fundamental tool in both scientific experiments and weather monitoring.

Photosynthesis is the process by which plants convert sunlight into chemical energy. This process uses water and carbon dioxide to produce glucose and oxygen, sustaining the plant.

Evaporation is the process by which water changes from a liquid state to a gaseous state when heated. It is an essential part of the water cycle that helps distribute water vapor in the atmosphere.

The mantle is the thick layer of rock situated directly below the Earth's crust. Its high temperatures and pressures cause the rock to behave in a semi-fluid manner over long periods.

Water is composed of two hydrogen atoms and one oxygen atom, which is denoted by the formula H2O. This simple molecule is critical for life and various chemical processes.

The heart is the muscular organ that continuously pumps blood throughout the body. Its rhythmic contractions are essential for maintaining the circulation of blood, nutrients, and oxygen.

Chlorophyll is the green pigment that absorbs sunlight, which is critical for the process of photosynthesis. This absorption enables plants to convert light energy into chemical energy.

There are eight recognized planets in our Solar System after Pluto was reclassified as a dwarf planet. This modern count follows the definitions set by the International Astronomical Union.

Newton's first law explains that an object will remain at rest or move in a straight line at constant speed unless a force intervenes. This property of motion is called inertia.

Oxygen is critical for cellular respiration in most living organisms, enabling cells to convert nutrients into usable energy. Without oxygen, the metabolic processes that sustain life cannot occur efficiently.

Under standard atmospheric pressure at sea level, water boils at 100°C. This boiling point is a consistent physical property used in numerous scientific calculations and experiments.

DNA acts as the blueprint for all living organisms by storing genetic information. This information directs cellular processes and is passed from one generation to the next.

Transpiration is the process by which plants release water vapor through small openings in their leaves called stomata. This process plays an important role in the water cycle and helps regulate the temperature of the plant.

Electrons, which orbit the nucleus, determine how atoms interact with each other during chemical reactions. Their arrangement in electron shells defines the chemical behavior and reactivity of the element.

A single displacement reaction involves one element displacing another from its compound based on reactivity. This type of reaction highlights the activity series of elements, where a more reactive element replaces a less reactive one.

A supernova is an explosive event that occurs at the end of a star's life cycle, releasing enormous energy and often outshining entire galaxies temporarily. This event disperses heavy elements into space, contributing to the formation of new stars and planets.

The phenotype refers to the observable traits of an organism, which are influenced by both its genetic makeup and environmental factors. This term distinguishes what is visible from the underlying genetic code (genotype).

The superposition principle states that, until measured, particles exist in a combination of all possible states simultaneously. This counterintuitive aspect of quantum mechanics challenges classical ideas and forms the basis for many modern technologies.