An element has the electron configuration 1s22s22p63s23p64s23d10. If the element forms an ion, what is its charge?
a) +1b) +2c) -2d) -6
e) 0, no ion is possible
When a pure solid substance was heated, a student obtained another solid and a gas, each of which was a pure substance. From this information which of the following statements is ALWAYS a correct conclusion?
a. both products are elements
b. both products are compounds
c. the original solid is...