Is exploding dynamite a chemical or physical property?

How is ti possible that, when adding protons while moving left to right across a period, the size of an atom shrinks? Why is the

Kaylis [27]

As one moves across a period, from left to right, both the number of protons and electrons of a neutral atom increase. The enhancing number of electrons and protons results in a greater attraction between the electrons and the nucleus. This uplifted attraction pulls the electrons nearer to the nucleus, therefore, reducing the size of the atom.

On the other hand, while moving down a group, there is an increase in the number of energy levels. The enhanced number of energy levels increases the size of the atom in spite of the elevation in the number of protons. In the outermost energy levels, the protons get attracted towards the nucleus, however, the attraction is less due to an increase in the distance from the nucleus.

4 0

3 years ago

Write the atomic symbol for the isotope of bismuth with 125 neutrons.

vlada-n [284]

First, isotopes are the atoms of a single element whose nuclei have a different number of neutrons, and therefore, differ in mass numbers. You should know that atoms are formed by a nucleus that has a small size and is made up of protons and neutrons. The nucleus is surrounded by a cloud of electrons, which are found in a region of the atom called the cortex.

The mass number, represented as A, is the sum of the number of protons and neutrons in the nucleus. On the other hand, the atomic number (Z) is the number of protons that exist in the nucleus.

The isotopes of an element X are represented as follows,

(see first attached picture)

It should be noted that the number of neutrons of a chemical element can be calculated as the difference A-Z.

The atomic and mass numbers of bismuth with 125 neutrons are:

Z = 83

A = 83 + 125 = 208

Thus, the atomic symbol of the bismuth isotope with 125 neutrons is:

(see second attached picture)