Chemistry
An atom of an element Y may be written as 94Y.
(a) What does the figure 9 indicate?
(b) What does the figure 4 indicate?
(c) What is the number of protons in atom Y?
(d) What is the number of neutrons in atom Y?
(e) What is the number of electrons in atom Y?
(f) How many electrons are there in the outermost shell of an atom of element Y?
(g) Write the symbol of ion formed by an atom of element Y?
Answer
(a) Mass number is indicated by figure 9, which is the sum of protons and neutrons in the nucleus of an atom.
(b) Atomic number is indicated by figure 4, which is the number of electrons present in a neutral atom.
(c) 4, as the atomic number also indicates the number of protons in the nucleus of an atom.
(d) 5, number of neutron = mass number - number of protons = 9-4=5
(e) 4, as the atomic number is 4, which is the number of electrons present in a neutral atom.
(f) 2, its electronic configuration is [2, 2]
(g) Y2+, as it has the valency of +2, hence it loses two valence electrons and becomes a positively charged ion.
Related Questions
(a) Name the charged particles which attract one another to form electrovalent compounds.
(b) In the formation of electrovalent compounds; electrons are transferred from one element to another. How are electrons involved in the formation of a covalent compound ?
(c) The electronic configuration of nitrogen is (2, 5). How many electrons in the outer shell of a nitrogen atom are not involved in the formation of a nitrogen molecule ?
(d) In the formation of magnesium chloride (by direct combination between magnesium and chlorine), name the substance that is oxidized and the substance that is reduced.
An element X has 2 electrons in its M shell, it forms bond with an element Y which has 7 electrons in its third orbit.
(a) Write the formula of the compound formed.
(b) Which nearest inert gas electronic configuration will element X and Y acquire?
(c) Show using an orbital diagram the formation of compound between X and Y.
Atom A is represented as 20982A, atom B as 20983B and atom C as 21182C
(a) How many electrons, protons and neutrons do A, B and C have?
(b) Which two atoms have the different number of nucleons?
(c) Name the term which can be used for A and C atoms.
(d) Define the term mentioned in part (c) above.
The atom of an element A has 6 electrons in its M shell.
(a) Write the electronic configuration of element A.
(b) What is the atomic number of element A?
(c) Is it a metal or a non-metal?
(d) What type of ion will be formed by an atom of element A? Write the symbol of the ion formed.
(e) What could element A be ?
(f) Draw the orbital structure of A and its ion.