This is how zirconium appears in the periodic table. A purple box has Z r at the center and 40 above. Below it says zirconium and below that 91.22.

Rounded to the nearest whole number, how many electrons are in an atom of zirconium?

40
51
91
131

- aluminum and copper chloride.

- the chloride ion to separate the aluminum from the oxygen so that the aluminum can react with the copper ions (and the water molecules).

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.

increased stability in the completion of fluorine's outer shell.