Which element would have this representation: 43 ? 21 question 4 options: technetium scandium titanium cobalt

The naswer to your question is Scandium

Explanation:

43 means the atomic mass is normally presented as a power

21 means atomic number is always a subscript

                   ₂₁ ? ⁴³

Technetium             ₄₃Tc⁹⁸

Scandium                 ₂₁Sc⁴⁴      

Titanium                   ₂₁Ti⁴⁷

Cobalt                      ₂₇Co⁵⁹

B. Scandium is the answer

Explanation:

When we look at this Nuclide symbol we get to know that 21 is the atomic number as it is in the subscript and 43 is the mass as it is in the superscript.

We identify an element from its atomic number by looking at the periodic table.

Atomic number 21 is element Scandium. Sc-43 is one of the isotope mentioned here.

We don’t use mass number to identify an atom.

it's c. elements are placed in rows based on how may valencies electrons have.

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