What is the atomic number and why is it important?
The number of protons in an atom is called its atomic number. This number is very important because it is unique for atoms of a given element. All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms.
Why is the atomic mass of chlorine is a fractional number?
Answer. Chlorine does not have fraction atomic number. It has atomic number 17, chlorine have fractional atomic mass number because it has two isotopes having atomic mass number 35 and 37 in the ratio 3:1.
Can modern periodic table solve all problems?
No, the modern periodic table cannot solve all the problem. Explanation: Modern periodic table is a better alternative than the other form of the periodic table.
How do we classify elements?
Elements can be classified as metals, metalloids, and nonmetals, or as a main-group elements, transition metals, and inner transition metals. Groups are numbered 1–18 from left to right.
How many types of elements are there?
118 different
How do scientists use properties to classify elements?
Some properties of an element can be observed only in a collection of atoms or molecules of the element. These properties include color, density, melting point, boiling point, and thermal and electrical conductivity. One major classification of the elements is as metals, nonmetals, and metalloids.
Which elements has the highest ionization energy?
The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.
What are the units of atomic radius?
Typical atomic radii have values of about one or two angstrom units. (One angstrom, 1 Å, equals 10−10 metre.)
What is formula of unit mass?
The mass of the formula unit of a substance is the sum of the atomic masses of all atoms in an ionic compound’s formula unit.