i. which of the following ti-lads does not follow Dobereirier’s law of triads? (a) Li, Na, K (b) Ca, Sr, Ba (c) Be, Mg, Ca

Question

Choose the correct option and rewrite the statement:

i. which of the following ti-lads does not follow Dobereirier’s law of triads? 

(a) Li, Na, K 

(b) Ca, Sr, Ba 

(c) Be, Mg, Ca 

(d) Cu, Ag, Au

ii. During Newlands time …….. elements were known. 

(a) 56 

(b) 65 

(c) 63 

(d) 36

iii. Halogens belong to group …….. in the modern periodic table. 

(a) 15 

(b) 16 

(c) 17 

(d) 18

iv. Noble gases belong to group …….. in modern periodic table. 

(a) 15 

(b) 16 

(c) 17 

(d) 18

v. The law of octaves was given by …….. 

(a) Dobereiner 

(b) Newlands 

(c) Mendeleev 

(d) Moseley

vi. Eka-boron was subsequently named as …….. 

(a) gallium 

(b)germanium 

(C) scandium 

(d) molybdenum

vii. The halogen which is liquid at room temperature is ……… 

(a) fluorine 

(b) astatine 

(C) bromine 

(d) iodine

viii. ……… is used in balloons and in scuba diving. 

(a) Helium 

(b) Oxygen 

(c) Nitrogen 

(d) Ozone

Answer 1

i. (d) Cu, Ag, Au

ii. (a) 56

iii. (c) 17

iv. (d) 18

v. (b) Newlands

vi. (C) scandium

vii. (C) bromine

viii. (a) Helium