chemical change

When two or more elements combine and form a compound, a chemical change takes place.

当两种或两种以上的元素结合形成化合物时，发生化学变化。

The chemical change gives off [ out ] heat and light.

这类化学变化发出 热乎 光.

Heat and light can be given off by this chemical change.

这种化学反应能放出热和光.

A chemical change takes place in any substance when it burns.

物质燃烧时产生化学变化.

New material can be brought about through chemical change.

通过变化可以生成新的物质.

The chemical change absorbing heat is named an end – thermal reaction.

吸收热量的化学反应被称为吸热反应.

The chemical change off heat and light.

这种化学变化发出热和光.

Wherever a chemical change takes place , there is a new substance formed.

每当发生化学反应, 都会产生新物质.

This chemical change can be expressed by an equation.

我们可用反应式表示这种化学变化.

A chemical change always results in forming at least on new substance.

一种化学变化总是产生至少一种新物质.

Microorganisms are the agents that bring about the chemical change.

微生物是引起化学变化的作用者.

We saw that a chemical change had taken place.

我们看到已发生了化学变化.

When rust is formed, a chemical change has taken place.

当锈生成时, 就发生了化学变化.

Whenever a chemical change takes place, There is a new substance formed.

每当发生化学变化时, 就有一种新的物质生成.

A chemical change takes place in paper when it burns.

纸燃烧时就发生了化学变化.