Which of the following corresponds to an alpha particle? A. A hydrogen nucleus, with an atomic number of 1 and an atomic
mass of 1
B. A helium nucleus, with an atomic number of 2 and an atomic
mass of 4
C. A helium nucleus, with an atomic number of 2 and an atomic
mass of 2
D. A helium nucleus, with an atomic number of 1 and an atomic mass
of 2

electron microscopy and scanning tunneling microscopes gives us a greater understanding of atoms by being able to see the atom itself, and lets us see some atomic reactions.

explanation:

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.