How many valence electrons are represented in the following electron configuration? 1s22s22p5

7 Valence Electrons.

Explanation:

The Valence electrons are referred to as the number of electrons in the outermost shell of an atom.

When given the electronic configuration, the valence can be calculated by adding the superscript of the hugest number coefficient.

The highest number coefficient in this electronc cnfiguration is 2. The sum of it's superscript is 2 (in 2s²) and 5 ( in 2p⁵). That is 2 + 5 = 7

How to test the answer?

The atom given has 9 electrons ( 2 + 2 + 5).

The K shell is being occupied by 2 electrons, the next shell; M shell which can occupy maximum of 8 electrons is being occupied by 7 electrons ( 9 - 7). And in this atom, the M shell is the outermost shell.

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).