The atomic number of an element is 9, it has 10 neutrons. Find the element from the periodic table. What will be its mass number?

टीपा लिहा

The element is Fluorine
Its mass number A
= n + p
= 10 + 9 = 19
∴Mass number of Fluorine = 19

shaalaa.com

या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?

पाठ 4: Atomic Structure - Evaluation [पृष्ठ ५२]

पाठ 4 Atomic Structure
Evaluation | Q VIII. 4. | पृष्ठ ५२

With the help of given Table, find out the mass number of oxygen.

Composition of Atoms of the First Eighteen Elements with Electron Distribution in Various Shells
Name of Element	Symbol	Atomic Number	Number of protons	Number of Neutrons	Number of Electrons	Distribution of Electrons				Valency
Name of Element	Symbol	Atomic Number	Number of protons	Number of Neutrons	Number of Electrons	K	L	M	N	Valency
Hydrogen	H	1	1	-	1	1	-	-	-	1
Helium	He	2	2	2	2	2	-	-	-	0
Lithium	Li	3	3	4	3	2	1	-	-	1
Beryllium	Be	4	4	5	4	2	2	-	-	2
Boron	B	5	5	6	5	2	3	-	-	3
Carbon	C	6	6	6	6	2	4	-	-	4
Nitrogen	N	7	7	7	7	2	5	-	-	3
Oxygen	O	8	8	8	8	2	6	-	-	2
Fluorine	F	9	9	10	9	2	7	-	-	1
Neon	Ne	10	10	10	10	2	8	-	-	0
Sodium	Na	11	11	12	11	2	8	1	-	1
Magnesium	Mg	12	12	12	12	2	8	2	-	2
Aluminium	Al	13	13	14	13	2	8	3	-	3
Silicon	Si	14	14	14	14	2	8	4	-	4
Phosphorus	P	15	15	16	15	2	8	5	-	3.5
Sulphur	S	16	16	16	16	2	8	6	-	2
Chlorine	Cl	17	17	18	17	2	8	7	-	1
Argon	Ar	18	18	22	18	2	8	8		0

Complete the following table.

From the symbol `""_15^31"P"`, state : atomic number of phosphorus

From the symbol `""_12^24"Mg"`
, state the mass number, the atomic number and electronic configuration of magnesium.

Draw the orbital diagram of `""_20^40"Ca"^(2+)` ion and state the number of three fundamental particles present in it.

Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.

Phosphorus – \[\ce{^31_15P}\]

[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]

From the symbol \[\ce{^4_2He}\] for the element helium, write down the mass number and the atomic number of the element.

Explain the following terms.

______ = No. of protons = No. of the electrons.

Electrons revolve around the nucleus in definite open shells.