Question

) If number of electrons and protons in an atom is 9 each, what is the atomic number of the element?

Answer 1

Answer:

Explanation:

atomic number=no of protons so atomic number-9

Answer 2

Answer:

In physics and chemistry, the atomic number1 of a chemical element is the total number of protons that each atom of that element has. It is usually represented by the letter Z.

Atoms of different elements have different numbers of electrons and protons. An atom in its natural state is neutral and has an equal number of electrons and protons. A sodium (Na) atom has an atomic number of 11; it has 11 electrons and 11 protons. A magnesium (Mg) atom has an atomic number of 12, has 12 electrons, 12 protons, and uranium (U) atom, which has an atomic number of 92, has 92 electrons, and 92 protons.

It is placed as a subscript to the left of the symbol of the corresponding element. For example, all the atoms of the element hydrogen have 1 proton and it's Z = 1; this would be ₁H. Those of helium has 2 protons and Z = 2; likewise, ₂He. Those of lithium, 3 protons and Z = 3 ...,

If the atom is neutral, the number of electrons coincides with that of protons and gives Z.

In 1913 Henry Moseley demonstrated the regularity between the values ​​of the wavelengths of X-rays emitted by different metals after being bombarded with electrons and the atomic numbers of these metallic elements. This fact allowed us to classify the elements in the periodic table in increasing order of atomic number. In the periodic table, the elements are ordered according to their atomic numbers in increasing order

Explanation: