The mass of a textbook was really heavy.
Hope I helped
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
I believe the best answer to that question wud be D. I cud b wrong
<span>The purpose of washing the product with NaOH is simply to
neutralize any acid which remained or leaked after the 1st initial
separation. The NaOH base reacts with the acid to form neutralization reaction products
which are soluble in water.</span>