Answer:
By definition, a pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers.
Explanation:
Sorry only knew the answer to the first question
The correct option is ARGON.
To quickly find out the element that is been described by the electronic configuration, write down and add together all the index figures in the electronic configuration. The index figures in the above electronic configuration are 2, 2, 6, 2 and 6. If you add all these figures together, you will get 18 and the element that has the atomic number of 18 is argon.
To me, I think the Earth was made around 6,000 years ago.
