Advertisements
Advertisements
Question
If an atom ‘A’ has mass number 35 and atomic number 17, state the number of protons, electrons and neutrons it contains.
Advertisements
Solution
Mass number = Number of protons + Number of neutrons
A = p + n A = 35 atomic number p = 17
∴ 35 = 17 + n
∴ n = number of neutrons = 35 – 17 = 18
n = 18
But p = e
∴ e = p = 17
Number of electrons = e = 17
APPEARS IN
RELATED QUESTIONS
The composition of the nuclei of two atomic species X and Y are given as under
| X | Y | |
| Protons | 6 | 6 |
| Neutrons | 6 | 8 |
Give the mass numbers of X and Y. What is the relation between the two species?
Fill in the blank
An ion which has a positive charge is called a ..................
ÅIn group I of the periodic table, three elements X, Y, and Z have ionic radii 1.33 Å, 0.95 Å and 0.60 Å respectively. Giving a reason, arrange them in the order of increasing atomic number in the group.
Fill in the Blank of the Following Statement :
An atom has atomic mass number 23 and atomic number 11. The atom has .................... electrons.
The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
The number of electrons in the atom of an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of an atom of this element ?
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]
Atomic number : ______ :: Mass number : Number of protons and neutrons.
The particles that make up the atom are called ______ particles.
Match the following:
| Column A | Column B | ||
| 1. | Mass of proton | a. | +1 |
| 2. | Mass of electron | b. | -1 |
| 3. | Charge of electron | c. | 9.31 x 10-28g |
| 4. | Charge of proton | d. | 1.67 x 10-24g |
