This state of matter has a fixed shape and volume, like a desk or a brick.
A: What is a solid?
This invisible force pulls objects down toward the center of the Earth.
A: What is gravity?
This primary source provides almost all the light and heat energy for our planet.
A: What is the sun?
This basic type of mixture is completely blended, like mixing spoonfuls of sugar into warm water.
A: What is a solution?
When iron is exposed to water and oxygen over time, it undergoes a chemical change to form this flaky red substance.
A: What is rust?
This state of matter takes the exact shape of whatever container you pour it into, like water in a glass.
A: What is a liquid?
This rubbing force slows down your sneakers when you slide across the gym floor.
A: What is friction?
This term describes energy that is stored and waiting to be used, like a stretched rubber band.
A: What is potential energy?
If you throw sand into a bucket of water, it doesn't dissolve. This makes it this non-blended type of mixture.
A: What is a heterogeneous mixture?
On the pH scale, liquids like lemon juice and vinegar are classified as this type of sour substance.
A: What is an acid?
This phase change happens when a liquid gets cold enough to turn directly into a solid.
A: What is freezing?
A compass needle always points north because the Earth behaves like a giant one of these objects.
A: What is a magnet?
This type of energy is the energy of actual motion, like a rolling bowling ball.
A: What is kinetic energy?
This is the lightest, simplest, and most abundant chemical element in the entire universe.
A: What is hydrogen?
This bubbly gas is what baker's yeast produces to make bread dough rise up fluffy in the oven.
A: What is carbon dioxide (CO2)?
This phase change occurs when liquid water sits in the sun and turns into an invisible gas.
A: What is evaporation?
This is the physical term for a push or a pull acting upon an object.
A: What is a force?
This is the scientific term for a light wave bending out of its straight path when it passes through a glass lens.
A: What is refraction?
This chart organizes all known chemical elements by their properties and atomic symbols.
A: What is the Periodic Table?
To neutralize a strong acid, you should mix it with one of these bitter substances, like baking soda.
A: What is a base (or alkaline)?
This rare, fourth state of matter is made of super-heated gas with an electrical charge, found in lightning bolts.
A: What is plasma?
This is the speed-slowing force that air pushes against a falling object, like a wide-open parachute.
A: What is air resistance (or drag)?
Unlike sound waves, light waves can travel through this completely empty environment where no air exists.
A: What is a vacuum (or outer space)?
This fundamental scientific rule states that matter cannot be magically created or destroyed in a reaction.
A: What is the Law of Conservation of Mass?
This special substance speeds up a chemical reaction without getting used up or changed in the process.
A: What is a catalyst?