Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
(b) When mass number is 18 and number of electrons is 7, then:
(i) No. of protons = No. of electrons = 7
(ii) No. of neutrons = Mass no. – No. of protons = 18 – 7 = 11
(iii)Atomic no. = 7
APPEARS IN
संबंधित प्रश्न
Fill in the blanks- The number of protons in the nucleus of an atom is called its ....................
From the symbol `""_12^24"Mg"`
, state the mass number, the atomic number and electronic configuration of magnesium.
From the symbol `""_2^4"He"` for the element helium, write down the mass number and the atomic number of the element.
Match the atomic numbers 4,8,10,15 and 19 with the following:
Element with four shells
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Carbon [At. no. = 6, Mass no. = 12]
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Sodium [At. no. = 11, Mass no. = 23]
A ______ number describes a specific aspect of an electron.
When an atom gives electrons from its outermost shell, it becomes ______ charged.
In a neutral atom number of protons is equal to the number of neutrons.
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 |
