A radioactive metal atom decays by emitting an alpha particle, which is a helium nucleus. The
alpha particles are collected as helium gas. A sample of helium with a volume of 12.05 mL was
obtained at 765 mmHg and 23 °C. How many atoms decayed during the period of the
experiment?

12. complete each of the following word equations for synthesis reactions. a. sodium + oxygen -> b. magnesium + fluorine -> 13. complete and balance the equations for the decomposition reactions. a. hgo -> [with the triangle heat symbol above the arrow] b. h2o(l) -> [with "electricity" written above the arrow]

List four observations that indicate that a chemical reaction may be taking place

What royal scientist used the 29th day of frozen vapor to encounter elements for mastering new culinary creations?