Answer is periodic because only happens in certain times
Answer:
When the solar system settled into its current layout about 4.5 billion years ago, Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust.
I think that building on a green hill
<em>The periodic table helps people understand what a substance's atoms can contain, which also provides information on how it can perform a specific action, or how well it can act as a base and so on. When people understand what something is made of, we can figure out what it can be used for. This makes it easier for workers to construct important structures.</em>
<em>Hope this helps and have a nice day.</em>
<em>-Sayonara</em>
