What percentage of a radioactive species would be found as daughter material after six half–lives?

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?

Pinene is an unsaturated hydrocarbon found in pine resin. if pinene has m+ = 136 and contains 1 double bond(s) and 2 ring(s); what is its molecular formula? enter the formula in the form ch first, then all other atoms in alphabetical order; do not use subscripts. the formula is case-sensitive