Can anyone solve this please. I need this fastly

Average atomic mass = 63.3896

Explanation:

Step 1: Find how much Cu-65 we have

1 - Amount of Cu-63 = Amount of Cu-65

1 - 0.6915 = Amount of Cu-65

Amount of Cu-65 = 0.305

Step 2: Find the average atomic mass of Cu

(0.6915 x 63) + (0.305 x 65) = Average atomic mass

(43.5645) + (19.825) = Average atomic mass

63.3895 = Average atomic mass

Therefore the average atomic mass of Cu is 63.3895 atomic mass units

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.