A molecule is a group of atoms linked with chemical bonds. It’s the smallest particle of a substance that has all of its chemical properties.
Breathe in and out, that’s respiration. Have a cell break down sugars for energy, and that’s respiration too.
Algebra is a type of mathematics that studies symbols and how they can be shifted around.
Medullary bone is a layer that forms inside bird and dinosaur bones. It’s a source of the calcium in eggshells.
Velocity is more than speed. It is both speed and the direction in which an object is traveling.
When it’s time for cells to die, they need to do it carefully, so they don’t harm other cells.
Puberty is a time when hormones surge and people develop the ability to have children. But it’s so much more than that.
Evolution is how species change over time. Individuals in the group vary, and some will pass on their genes. Over time, the whole species changes.
Nucleus comes from the Latin term “nuc,” meaning nut or kernel. In science there are lots of nuclei. Every one of them is the center of something.
An earthquake is a sudden and sometimes violent shaking of the ground.
Scientists refer to a narcotic as a drug that stops pain, but the word can be used in other ways as well.
Gravity is a fundamental force that attracts objects with mass to other objects with mass. It decreases with distance.