Chemistry
This gas makes up 78% of the Earth's atmosphere
Nitrogen
This organ pumps blood throughout the human body
The heart
The unit used to measure force in the metric system.
Newtons
This is the name for a number that has only two factors: 1 and itself.
A prime number
This element has the symbol 'Na' and is a highly reactive element which reacts violently with water
Sodium
Photosynthesis occurs in this green plant cell organelle.
The chloroplast
This force causes rubbing surfaces to slow down and produce heat.
Friction
The sum of the angles in a triangle always adds up to this many degrees
180
The pH scale measures how acidic or basic a substance is. A substance with a pH of 11 is called ___
Basic
The process by which animals adapt to their environment over time
Evolution
The Moon’s gravity causes this natural movement of ocean water on Earth.
Tides
This is the value of 3² + 4²
25
This scientist created the first periodic table of elements.
These blood cells help fight infections in the human body.
White blood cells
The speed of light is approximately ___ kilometers per second.
300,000 km/s
This type of triangle has two sides of equal length
Isoceles
This type of reaction occurs when a substance gains oxygen or loses electrons.
These tiny hair-like structures in the respiratory tract help filter out dust and microbes.
Cilia
This type of energy is stored in a stretched rubber band or compressed spring
Elastic Potential Energy
The number π (pi) is approximately equal to this decimal value
3.14