what is the half life isotope if after 21 days you have 31.25 g remaining from a 250.0 g starting sample size?

Do two objects with the same mass always have the same volume

Which bond is least polar? As-Cl, Bi-Cl, P-Cl, N-Cl

What happens to an electron during an electron transition? A. The electron gains mass and falls into the nucleus of the atom. B. The electron flows between continuous energy levels when it gains or loses energy. C.

A scientific has a lot of support and is more than just a hunch

As a radioactive element emits gamma radiation only, the atomic number of the element

What is the percent by mass of nahco3 in a solution containing 10 g of nahco3 dissolved in 400 ml of h2o?

Consider the reaction: 2clf3 (g) + 2nh3 (g) → n2 (g) + 6hf (g) + cl2 (g) when calculating the δh°rxn, why is the δhf° for n2 not important?

12.5 g of copper are reacted with an excess of chlorine gas, and 25.4 g of copper (II) chloride are obtained. Calculate the theoretical yield and the percent yield.

Section 20.1 the meaning of oxidation and reduction answer key

How did fossil fuels come about? inorganic materials beneath the sea the remains of plants and animals millions of years old only dinosaur fossils sedimentary rocks on the tops of mountains