What is the half - life formula

An unknown radioactive substance has a half-life of 3.20 hours. If 16.5 g of the substance is currently present, what mass A0 was present 8.00 hours ago

Which of the following statement (s) is/are TRUE? Intermolecular forces hold the atoms in molecules together. Vapor pressure increases with temperature. Dispersion forces are generally stronger than dipole-dipole forces.

Chlorine gas can be prepared in the laboratory by the reaction of hydrochloric acid with manganese (IV) oxide. 4 HCl (aq) + MnO 2 (s) ⟶ MnCl 2 (aq) + 2 H 2 O (l) + Cl 2 (g) 4HCl (aq) + MnO2 (s) ⟶MnCl2 (aq) + 2H2O (l) + Cl2 (g) A sample of 43.

2 Na Cl2 2Naci sodium chloride 2. In the above reaction, what is the product? A Na, C, and I B Na, CI C NaCl D Na, Cl, and Naci

If Earth had only half as much mass as it currently does, how would this affect the force of gravity between the moon and Earth? A. The force of gravity would remain the same. B. The force of gravity would be half what it currently is. C.

How many moles are in 16.94g of water?

Two compound samples are found to have the same mass percentages of the same elements. what can you conclude about the two samples

Sodium hypochlorite (Na xCl yO z) is the active ingredient in household bleach. A 250.0 g sample of sodium hypochlorite contains 77.2 g sodium, 119.1 g chlorine, and the remainder is oxygen. Calculate the empirical formula of sodium hypochlorite.

The tapeats sandstone in the grand canyon is an example of a clastic sedimentary rock. such clastic sedimentary rocks can be distinguished from biochemical sedimentary rocks by

An ice cube and a scoop of table salt are left outside on a warm, sunny day. Explain why the ice cube melts and the salt does not