The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer:
C
Explanation:
A physical change is when the form of the matter is just altered. While a chemical change results from a chemical reaction. No reaction is happening during the mixing of the two colors [nothing is boiling, freezing, evaporating, melting ext.] , but after you mix them the end result does look different. That only because we changed the physical properties of it.
(B is not a physical change because the baking powder inside of the cake must under go a reaction that causes the cake to rise. )
No, some impurities may alter the observed effects of a chemical reaction.. during a reaction other products may be produced, they may alter the MP or BP of the pure substance.