<u>Any of five chemical substances that are not metals and that combine with hydrogen to form strong acid compounds from which simple salts can be made</u>
Answer:
Single replacement reaction (aka single displacement reaction)
Explanation:
In a single replacement reaction, one element is substituted for another in a compound to create a new compound and a new element in the products. The general form is:
A + BC --> B + AC
In the case of this question, Cr and Fe "trade places."
The heavy one because mass times force is equal to speed. The lighter one has less mass to it goes faster without as much effort. I hope that helps!
B: dna cells should be the answer
