Q.1) What are chemical symbols?
Q.2) How many Oxygen atoms are in the chemical formula of 2Fe2O3 ?
Q.3) How many elements are in C6H12O6?
Q.4) What is Atomicity and Valency?
Q.5) What is the valency of Ferrous and Ferric?
Q.6) How Valency is calculated? Give valency of first 20 elements.
Q.7) An element X has valency 3. Write the formula of its oxide.
Q.8) Write the electronic configuration of the following atoms and the valency from th arrangement of the electrons
(a) Sodium
(b) Phosphorus
(c) Sulphur
(d) Argon
(e) Zinc
(f) Krypton
Q.9) Write the differences between Physical and Chemical changes.
Q.10) Give an example of a physical change which occur by the action of heat.
Q.11) How can you say that ripening of fruits is a chemical change?
Q.12) In addition to the formation of new products,what changes do the chemical changes accompany?
Q.13) How many O's are in Al2(sO4)3 ? Q.14) Number of H in 3(NH4)2Cro4 ?
Q.15) How many atoms are there in total -H2SO4?
Dear student,
(1) The chemical symbol can be defined as an abbreviation for a chemical element.
(2) 6 oxygen atoms are in 2Fe2O3.
(3) In the compound C6H12O6 has 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen.
(4) Atomicity can be described as the number of atoms present in a molecule while the valency can be described as the number of electrons that an atom has to lose or gain for the stability.
Regards
(1) The chemical symbol can be defined as an abbreviation for a chemical element.
(2) 6 oxygen atoms are in 2Fe2O3.
(3) In the compound C6H12O6 has 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen.
(4) Atomicity can be described as the number of atoms present in a molecule while the valency can be described as the number of electrons that an atom has to lose or gain for the stability.
Regards