1 A student reacted excess calcium with hydrochloric acid.
Grade
1.1 Explain why calcium was added in excess.

In which layer of earth do most earthauakes occur a_ inner core b_outer core c_mantle d_crust

Which of the following pressures is equal to 760 mm hg? 2.0 atm 101.3 pa 101,300 kpa 101,300 pa

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth