Explanation:
Percentage composition of oxygen = (80/134) * 100% = 59.7%.
They can use them to find the age of fossils.
The magnetic fields are the reason why magnets repel and attract. eachother.
Answer:
That is a compound. If it was an element it would either just be Na or Cl.
Answer:
Cupric oxide, or copper (II) oxide,
Explanation:
Correct me if im wrong tnx:<