oxidation

一种化学物质，通常尝起来是酸的，有时能溶解东西。在科学上，它是一种pH值小于7的液体。

这是数学的一个分支，通过使用字母和符号来代表方程中的未知数，从而计算出结果。

An atom is the smallest possible part of a chemical element. Everything in the world is made of millions of these very tiny particles.

Atomic relates to the very small parts called atoms that make up everything in the world. It is often used to describe science, energy, or very small things.

Calculus is a high-level branch of mathematics that studies how things change. It uses special symbols to calculate things like the speed of an object or the area of a shape.

A catalyst is something that makes a change happen faster or more easily. In science, it is a substance that speeds up a chemical reaction without being changed itself.

电路是电流流过的完整路径。它就像一个封闭的圆圈。

The circumference is the distance around the outside edge of a circle or a round object. It is a measurement that tells you how long the boundary of a round shape is.

A constant is something that stays the same and does not change. In science and math, it is a fixed number or a part of an experiment that is kept the same while other things vary.

A decimal is a number that uses a dot to show parts of a whole. It is based on the number ten and helps show values smaller than one.