Chemistry - Study Mode

[#676] Atoms having the same number of protons but different number of neutrons are called :
Correct Answer

(A) Isotopes

Explanation

Solution: Two atoms with the same atomic number, but different mass numbers (same number of protons, different number of neutrons), are called isotopes, or isotopic nuclides.

[#677] Chemical properties of isotopes
Correct Answer

(A) Must be same

Explanation

Solution: Different isotopes of an element generally have the same physical and chemical properties. That's because they have the same numbers of protons and electrons.

[#678] Which of the following does the nucleus of an atom consists of?
Correct Answer

(A) Protons and neutrons

Explanation

Solution: The nucleus of an atom consists of neutrons and protons, which in turn are the manifestation of more elementary particles, called quarks, that are held in association by the nuclear strong force in certain stable combinations of hadrons, called baryons.

[#679] The mass number of a nucleus is
Correct Answer

(D) Sometimes more and somtimes equal to its atomic number
(F) the sum of the number of protons and neutrons present in the nucleus

Explanation

Solution: The mass number (A), is the total number of protons and neutrons in an atomic nucleus so sometimes more than and sometimes equal to its atomic number, depends upon no of neutrons.

[#680] The metal ion present in Vitamin B12 is
Correct Answer

(B) Cobalt

Explanation

Solution: The structure of B 12 is based on a corrin ring, which is similar to the porphyrin ring found in heme, chlorophyll, and cytochrome. It contains the biochemically rare element cobalt sitting in the center of the ring. Also called cobalamin, it is a water-soluble vitamin.