Question

An atom with 3 protons and 4 neutrons will have a valency of :
A.3
B.7
C.1
D.4

Answer 1

Hint: The smallest unit of ordinary matter that makes up a chemical element is an atom. Atoms that are neutral or ionised make up every solid, liquid, gas, and plasma. Atoms are very tiny, measuring around 100 picometers in diameter. Due to quantum phenomena, it is impossible to correctly anticipate their behaviour using traditional physics—as if they were tennis balls, for example.

Complete answer:
The electromagnetic force attracts an atom's electrons to its protons in the atomic nucleus. The nuclear force attracts protons and neutrons in the nucleus to each other. The electromagnetic force that repels positively charged protons from one another is generally stronger than this force. Under some conditions, the electromagnetic force repelling the nuclear force grows greater. The nucleus breaks in this scenario, leaving behind several components. The atomic number is the number of protons in the nucleus that determines the chemical element the atom belongs to. Copper, for example, is any atom with 29 protons. The amount of neutrons in an element determines its isotope. Chemical bonds allow atoms to join with one or more other atoms to create chemical compounds such as molecules or crystals. Most of the physical changes observed in nature are due to atoms' capacity to associate and disassociate. Chemistry is the branch of science that investigates these changes. In chemistry, an element's valence or valency is a measure of its ability to combine with other atoms to create chemical compounds or molecules. The electrical configuration of an element with three protons is 2, 1, and it has three electrons. As a result, it would gain a stable duplet by shedding the outermost electron. As a result, its valency is +1.
Hence, the correct option is C.

Note:
The IUPAC defines valence as the maximum number of univalent atoms (initially hydrogen or chlorine atoms) that can combine with an atom of the element under discussion, a fragment, or be replaced for an atom of this element. The amount of hydrogen atoms that can mix with an element in a binary hydride, or twice the number of oxygen atoms that can react with an element in its oxide or oxides, is an alternate contemporary definition.