Answer: Melting or boiling
Explanation:
Melting or boiling point is another property that scientists can use to identify a substance. Melting point is the temperature at which a substance changes from solid → liquid. Boiling point is the temperature at which a substance changes from liquid → gas.
Volume of water displaced is equal to the volume of the metal. So 41 - 20 = 21 ml. Density = mass / volume so density = 159 / 21 = 7.57 g/ml
Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc = 
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required = 
So



Answer:
because they need only one electron