General
Water boils at this temperature on the Celsius scale.
100 degrees
This scientist came up with the theory of relativity.
Albert Einstein
This organ pumps blood throughout the body.
heart
This is the layer of gases that surrounds Earth.
atmosphere
This branch of science studies matter and its interactions.
chemistry
He invented the first practical telephone.
Alexander Graham Bell
This is the largest organ of the human body.
skin
This layer of Earth lies just below the crust.
mantle
This gas makes up the majority of Earth’s atmosphere.
nitrogen
This American scientist helped develop the polio vaccine.
Jonas Salk
These bones protect your brain.
skull
This scale is used to measure earthquake strength.
Richter scale
This force keeps planets in orbit around the sun.
gravity
This woman conducted pioneering work on radioactivity.
Marie Curie
This part of the eye controls how much light enters.
pupil
The water cycle includes evaporation, condensation, and this.
precipitation
This man developed the theory of evolution by natural selection.
Charles Darwin
This German physicist won the Nobel Prize for explaining the photoelectric effect.
Albert Einstein
These cells help the body fight off infections.
white blood cells
This type of rock is formed by cooling lava or magma.
igneous rock
The study of earthquakes is called this.
seismology
This Italian scientist improved the telescope and supported heliocentrism.
Galileo Galilei
This system includes the brain and spinal cord.
nervous system
This is the name for permanently frozen ground found in the Arctic.
permafrost
This law says for every action there is an equal and opposite reaction.
Newton's Third Law
This ancient Greek is known as the "father of medicine."
Hippocrates
This hormone regulates blood sugar.
insulin
The Earth's magnetic field is generated by this layer.
outer core