Advertisements
Advertisements
Question
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Lithium [At. no. = 3, Mass no. = 7]
Advertisements
Solution
Structure of atoms:

Z is Atomic Number A is the mass number
Lithium \[\ce{^7_3Li}\]
Z = 3 = p = e
K L
e = 3 = 2, 1
A = p + n
7 = 3 + 3
∴ n = 7 − 3 = 4
APPEARS IN
RELATED QUESTIONS
State the mass number, the atomic number, number of neutrons and electronic configuration of the following atoms.
`""^12""_6C, ""^16""_8O, ""^19""_9F, ""^20""_10Ne, ""_13""Al""^27, ""_17""Cl""^35`
Also, draw atomic diagrams for them.
What is variable valency? Name two elements having variable valency and state their valencies.
Fill in the following blanks :
| Atomic Number | Mass Number | Protons | Neutrons | Electrons | Symbol |
| 10 | 22 | _________ | _________ | _________ | _________ |
The mass number of an element is 18. It contains 7 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
The atomic number of four elements A, B, C and D are 12, 13, 15 and 3 respectively. The element which cannot form a cation is :
What is the significance of atomic numbers in the modern Periodic Table?
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
A ______ number describes a specific aspect of an electron.
‘Z’ is denoted by ______.
If an atom has 6 electrons in its outermost shell, it is inert.
