我们从质子数开始。

And we began with the proton number.

youdao

质子数是在左下方。

The proton number is in the lower left corner.

youdao

它是质子数加上中子数。

This is sum of protons plus neutrons.

youdao

每个周期中元素的质子数从左到右递增。

In each period, the atomic number of each element is increasing.

youdao

一种元素的原子序数是其原子核中的质子数。

An element's atomic number is the number of protons in its nucleus.

youdao

一种元素的原子序数是其原子核中的质子数。

An element's atomic number is the number of protons in its nucleus.

youdao