If an element forms a 1- ion in which group of the periodic table would you expect to find it a) 1
b) 17
c) 2
d) 18

Explanation:

Since it forms a 1- ion, it gains an electron to fulfill its stable octet structure. This means it had 8 - 1 = 7 valence electrons. => Group 17. (B)

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it