Convert to decimal number: 2/5

2:5=0,4

What is the point of throwing salt on the street during the winter when it is very cold ( temperatures in minuses)?

In order to lower the melting point of the water and there is no ice on the street.

There is sodium ion, potassium ion and chlorine ion in the bowl. How does sodium ion know which one to choose for making compound?

Na+, K+, Cl- plus goes with minus, not with plus.