Periodic Classification of Elements

Because calcium (Ca) has a 20 atomic number(Z), the Electronics configuration is  1s2,2s2, 2p6,3s2,3p6,4s2. its electronic arrangement is 2, 8, 8, 2. Calcium, therefore, has two valence electrons. The element with atomic number 12 has an electrical configuration is 1s2,2s2, 2p6,3s2, Its electronic arrangement is 2,8.2. The element that most closely resembles calcium has two valence electrons.

The periodic table position of an atom is determined by the number of valence electrons, whereas the number of valence electrons is determined by the electronic configuration of the atom.

The atomic number of Nitrogen is 7, Electronic configuration of Nitrogen is 1s2,2s2,2p3 The atomic number of Phosphorus is 15 , Electronic configuration of Phosphorous is 1s2,2s2,2p6,3s2,3p3 On moving top to bottom a group in the periodic table, the number of shells increases. Due to this, valence electrons move away from the electrons and the …

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why? Read More »

(a) Element A is a non-metal(b) Element C is less reactive than Element A(c) C is smaller in size than B(d) A will form an anion.

(a)The element with electronic configuration (2,8,7) means 17 is chlorine. The no. of atomic number(Z) = no. of electrons(e) Therefore, the atomic number is 17. (b) An atom with electronic configuration 2, 8, 7 would be chemically similar to F (At. No. 9) because it has electronic configuration 2,7, Both have 7 electrons in the …

An atom has electronic configuration 2, 8, 7.
(a) What is the atomic number of this element?
(b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.) N(7), F(9), P(15), Ar(18) Read More »

(a) Group 13 includes all of the elements that are found in the same column as boron. They each have three electrons in their valence shells as a result. All of the other elements in this group, including aluminium, gallium, indium, and thallium, are metals with the exception of boron, which is a non-metal. (b) …

(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common? Read More »

(a) Neon contains two full shells. (b) The electronic configuration of magnesium is 2, 8, 2. (c) Silicon has four electrons in its valence shell and a total of three shells. (d) Boron has three electrons in its valence shell and a total of two shells. (e) The second shell of carbon has twice as …

Which element has?
(a) Two shells, both of which are completely filled with electrons?
(b) The electronic configuration 2, 8, 2?
(c) A total of three shells, with four electrons in its valence shell?
(d) A total of two shells, with three electrons in its valence shell?
(e) twice as many electrons in its second shell as in its first shell? Read More »

The answer is Magnesium (Mg), It has a valency of 2, which is the same as the group (a) Na (b) Mg (c) AI (d) Si Also, Mg, when combined with chloride, forms Magnesium Chloride ( MgCl2).

The atoms lose their electrons more readily, hence the right response is c. The claim that atoms lose electrons more readily is untrue since the non-metallic character rises as we move from left to right across the periods of the periodic table. As a result, there is less of a tendency to lose an electron.

Be and Ga are to be the most metallic. In Be and Ga, Ga is bigger in size and hence has a greater tendency to lose electrons than Be. Therefore, Ga is more metallic than Be.