Solve this riddle. I am an atom with a mass number of 23 and 11 protons. Class 9

Solve this riddle. I am an atom with a mass number of 23 and 11 protons. Class 9

Question 1.

Solve this riddle: I am an atom with a mass number of 23 and 11 protons. I am a soft metal and react vigorously with water. Who am I and how many neutrons do I have? You can also create one such riddle. (Page 152) Class 9

Answer:

1. Mass number = 23, number of protons (atomic number) = 11.
2. Number of neutrons = 23 - 11 = 12.
3. The element with atomic number 11 is Sodium (Na). Sodium is indeed a soft metal that reacts vigorously with water.

Answer: I am Sodium (Na) and I have 12 neutrons.

Question 2.

Two different atoms have 11 protons each, but one has 12 neutrons, and the other has 13 neutrons. How do their atomic numbers and mass numbers compare? Are they the same element or different elements? (Page 156) Class 9

Answer:

1. Both atoms have 11 protons, so both have atomic number =11.
2. Since the atomic number is the same, both atoms belong to the same element - Sodium (Na).
3. Mass number of first atom = 11 + 12 = 23.
4. Mass number of second atom = 11 + 13 = 24.
5. So their atomic numbers are the same but their mass numbers are different.
6. These two atoms are isotopes of sodium - they are the same element but with different mass numbers.