Copper has two stable isotopes 63cu and 65cu. 63cu has an abundance of 69.09%. the other isotope, 65cu, has an abundance of 30.91%. calculate the average atomic mass of copper.

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent

Reactions in cells take place at about a. 40°c b. 0° c. 100°c d. 60°c

How can a ringing telephone can be heard through a closed door