Using the periodic table entry of iron below, match the numbers with what they represent. 1. the number 26 atomic number 2. the number 56 number of valence electrons 3. the number 4 number of orbits 4. the number 30 atomic mass 5. the number 14 number of neutrons 6. the number 2 5 number of electrons in n = 3

Answers:

1. The number 26 ↔ atomic number

2. The number 56 ↔ mass number

3. The number 4 ↔ the number of orbits

4. The number 30 ↔ number of neutrons.

5. The number 14 ↔ number of electrons in n = 3

6. The number 2 ↔ number of valence electrons.

Explanation:

The same relevant information to deal with the data reported can be found in many periodic tables.

Herewith, I copy the mentioned entry. Please see the image attached.

This is the explanation of the information shown in the entry:

1) Symbol: in the centre of the picture: Fe. It is the symbol of iron.

2) Superscript to the lef of the symbol: 26. It is the atomic number, i.e. the number of protons. Hence, this is the first match:

          1. The number 26 ↔ atomic number

3) The number 55.845 below the symbol and name of the element is the atomic mass of the element.

The atomic mass is the avereage mass of the several isotopes of the same element that exist in nature.

The particles that count for the atomic mass are the neutrons and protons, and that is reason of the called mass number, which is the sum of the neutrons and protons of a particular isotope.

An atomic mass of 55.845 means that likely there exist isotopes with mass number 56. This is, with a total number of 56 nucleons (protons and neutrons).

Since, as explained above, Fe has 26 protons, you can calcualte the number of neutrons of the 56 mass number isotope as: n = 56 - 26 = 30 neutrons.

Hence, you can match these:

         2. The number 56 ↔ mass number

         4. The number 30 ↔ number of neutrons

5. The numbers 2, 8, 14, and 2, that appear in the upper right corner of the image are the number of electrons in the different main energy levels, which is the principal quantum number (n)

They mean:

energy level (n)      number of electrons

  1                               2

 2                               8

 3                              14

 4                             2

Hence you can match this:

5. The number 14 ↔ number of electrons in n = 3

6. The number 2 ↔ number of valence electrons

The valence electrons are the electrons in the last main energy level (here n = 4).

3. The number 4 ↔ the number of orbits

Note: orbits is not a good name for the energy levels, since orbits implies fixed paths around the nucleus and that is an overcome model.