There are 11 electrons in Sodium(Na)
The first shell can hold 2 electrons
The second shell can hold 8 electrons
The third shell can also hold 8 electrons but there is only 1 left
so the answer is 2, 8, 1
Nitrogen molecule is diatomic, whereas other elements form tetraatomic molecules.
Hydrosphere, atmosphere, geosphere, biosphere, anthrosphere.
Hydrosphere: Liquid, vapour or ice.
Atmosphere: Oxygen.
Geosphere: Minerals.
Biosphere: Ecosystem.
Anthrosphere: Human habitats
The elemental symbol of gold is denoted on the periodic table as being Au.
There are 18. In each molecule of Fe(NO3)2 there are 6 oxygen atoms because you have 2 nitrate (NO3) components which each contain 3 oxygen atoms. 2 x 3 = 6. Because you have 3 molecules of Fe(NO3)2, you need to multiply 6 by 3, which gives you 18 oxygen atoms.
