Each proton and each neutron contribute amu to an atom. Amu means .

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %

Stoichiometry- i need with 14 and 15! an explanation would be appreciated!

Dona wrote the characteristics of two types of galaxies as shown below: type a: has a large flattened core type b: does not have a regular shape which statement is correct? type a is an irregular galaxy and type b is a lens galaxy. type a is a lens galaxy and type b is an irregular galaxy. type a is a spiral galaxy and type b is an elliptical galaxy. type a is an elliptical galaxy and type b is a spiral galaxy.