It is softer than topaz and and it is softer than diamond (diamond has a Mohs hardness of 10, which is the highest value of the scale)
Answer:
Protons = 17 Neutrons = 18 Electrons = 17
Explanation:
The number of protons and electrons are the the same number as the atomic number.
To get the number of neutrons, subtract the number of protons from the mass number.
35-17=18
Answer:
Element Lithium
Explanation:
The element with the highest second ionization energy is lithium. It belongs to the alkaline metal group I.e group one metals
It has the highest second ionization energy because it is very difficult to remove the electron from the 1s orbital.
Its atomic number is 3. The electronic configuration is 1s2 2S1
