100 brainliest if correct!

which concentration of hydrochloric acid would most likely react with a zinc metal strip at the fastest rate?
a. 10%
b. 20%
c. 30%
d. 40%

The reaction is Zn + 2HCl -> ZnCl2 + H2

Its reaction rate will go up with more HCl as in a higher concentration. So the answer is D. 40%

the answer is na (sodium)

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.