alleryStart learning →The atomic number of an element equals its number of:
AValence electrons
BNeutrons
CProtons plus neutrons
DProtons
Answer & Solution
Correct answer: D. Protons
1. Atomic number Z is the count of protons in the nucleus.
2. It uniquely identifies an element.
3. Mass number A = protons + neutrons.
4. So atomic number equals number of protons.
_Source: Selina Concise Chemistry ICSE Class 9, Ch 4 'Atomic Structure'_
Keep practising Atomic Structure
Browse all Atomic Structure questions for ICSE Class 9, or explore more Chemistry topics.
Related questions
Which sub-particle was discovered LAST?If an element has the configuration 2, 8, 8, 1, its valency and likely group are:Why does the atomic mass of chlorine (35.5) lie between two integers?An atom of oxygen has Z = 8 and A = 16. Number of neutrons is:Why are protons and neutrons together called nucleons?Isotopes of hydrogen include:Chlorine (Z = 17) becomes Cl- by gaining how many electrons?Magnesium (Z = 12) forms Mg^2+ by losing how many electrons?