www.bbcnoun.com.ng CHM101 8/10 1.P - block elements are elements in groups ____________. 13 to 18 2. S- block elements are _________. group 1 and 2 elements 3. If the bond length in a XY molecule is 212, what will be the covalent radius of atom X, if the covalent radius of Y atom is 93. 2.27 4. The first element on the periodic table is _____________. hydrogen 5. Normal representative or main group elements are ________. the s and p block elements 6. Electronegativity ____________ of S and P block elements. increases across the period 7. The s- block elements are elements in which the ________ enters the s atomic orbital last electron 8. D and F - block elements are also known as ____________. transition and inner transition elements 9. The energy required to remove the least strongly bond electron from an isolated gaseous atom in its ground state is known as the ____________. ionization energy 10. Which of this statement is correct ____________? Atomic radius decreases across a period because, across the period effective nuclear charge increases, exerting greater force on the outer most electron, hence pulling the electron cloud of the outer most shell inward nearer the nucleus.