# What is atomic number and mass number with example?

## What is atomic number and mass number with example?

(i) Atomic number: The atomic number is the total number of protons present in the atom. For example, the atomic number of Mg is 12. It contains 12 protons and 12 electrons. (ii) Mass number: It is the sum of the number of neutrons and the number of protons.

What is atomic number and mass number of an element?

(a) Atomic number is the number of protons in one atom of an element. Mass number is the total number of protons and neutrons present in one atom of the element.

What are 2 examples of atomic mass?

Atomic Mass Examples The atomic mass of most sodium atoms is about 23 amu, because of their 11 protons and 12 neutrons. The average atomic mass of oxygen is 22.99 amu because of the varying isotopes of sodium. The atomic mass of most copper atoms is about 63 amu, because of their 29 protons and 34 neutrons.

### What are the first 20 elements and their atomic mass?

1. What is the Atomic Mass of the First 20 Elements?

Atomic Number Element Atomic Mass
17 Chlorine 35.45
18 Argon 39.948
19 Potassium 39.098
20 Calcium 40.078

What is a atomic number example?

The atomic number of an atom is equal to the number of protons in the nucleus of an atom or the number of electrons in an electrically neutral atom. For example, in a sodium atom, there are 11 electrons and 11 protons. Thus the atomic number of Na atom = number of electrons = number of protons = 11.

What is Class 9 mass number example?

ii) Mass number is the number of protons and neutrons in the nucleus taken together. For example, mass number of sodium is 23 g/mol. iii) Isotopes are elements with the same atomic number but different mass numbers. Example, hydrogen has 3 isotopes – protium (1H1), deuterium (2H1) and tritium (3H1).

## What is the atomic mass of first 30 elements?

Atomic Mass of First 30 Elements

ATOMIC NUMBER ELEMENT ATOMIC MASS
27 Cobalt 58.933
28 Nickel 58.693
29 Copper 63.546
30 Zinc 65.38

Which element has an atomic number of 12?

Magnesium
Magnesium – Element information, properties and uses | Periodic Table.

What is the atomic mass of 1 to 30 elements?

Atomic Mass of First 30 Elements

ATOMIC NUMBER ELEMENT ATOMIC MASS
1 Hydrogen 1.008
2 Helium 4.0026
3 Lithium 6.94
4 Beryllium 9.0122

### What is atomic number of an element?

The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).

What are the 118 types of elements?

118 Elements and Their Symbols and Atomic Numbers

Name of the Element Symbol of the Element Atomic Number
Carbon C 6
Nitrogen N 7
Oxygen O 8
Fluorine F 9

What is mass number explain with example?

(ii) Mass number: It is the sum of the number of neutrons and the number of protons. For example, the atomic number of magnesium is 12 which is equal to the number of protons, the number of neutrons of magnesium is 12. The mass number is equal to 24 (12+12).

## What is atomic number example?

What is the atomic number of an element?

What is the atomic mass of element 118?

295.216u
Oganesson is a chemical element with symbol Og and atomic number 118….Oganesson.

Atomic Mass 295.216u
Year Discovered 2006

### What is the atomic mass of element 21?

Scandium 44.956
Atomic Mass of First 30 Elements

ATOMIC NUMBER ELEMENT ATOMIC MASS
21 Scandium 44.956
22 Titanium 47.867