An atom has 13 protons and 14 neutrons. what is its mass number?

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

In a copper wire, a temperature increase is the result of which of the following

Which statement explains why the bonds between non metals tend to be covalent? the bonds are found to be nondirectional they have large differences in electronegativity they have small differences in electronegativity they have ions that produce an electrostatic pull