What is the identity of the element that has 19 protons and 22 neutrons?

Ibeg i need 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

Indicate whether the specified alkyl halides will form primarily substitution products, only elimination products, both substitution and elimination products, or no products when they react with sodium methoxide. 1-bromobutane 1-bromo-2-methylpropane 2-bromobutane 2-bromo-2-methylpropane

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