Shaalaa.com | Periodic Classification of Elements part 11 (Questions)
Rewrite the following statement after correction, if necessary:
Isotopes are the elements of the same group.
State whether the following statement is true of false:
The elements in a group have consecutive atomic numbers.
Find the neutral atom in the periodic table which has the same number of electrons as K+ and Cl−. What is this number?
As element X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong?
An element Y is in second period and group 16 of the periodic table:
(i) Is it a metal or non-metal?
(ii) What is the number of valence electrons in its atom?
(iii) What is its valency?
(iv) What is the name of the element?
(v) What will be the formula of the compound formed by Y with sodium?
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electron shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound. This ionic compound is added in a small amount to almost all vegetables and dishes during cooking. Oxides of elements A and B are basis in nature while those of elements E and F acidic. The oxide of element D is, however, almost neutral. Based on the above information, answer the following questions:
(a) To which group or period of the periodic table do these elements belong?
(b) What would be the nature of compound formed by a combination of elements B and F?
(c) Which two of these elements could definitely be metals?
(d) Which one of the eight elements is most likely to be found in gaseous state at room temperature?
(e) If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write formula of the compound formed by the combination of C and G.