Answer:
the answer choice is B
Explanation:
as we move from left to right , the atomic size decreases due to higher number of protons in the nucleus, which are able to attract the electrons more strongly. and so the electronegativity and electron affinity increases for the same reason. the nuclear charge increase due to more protons , and without an increase in inner electrons , there is less shielding effect. so effective nuclear charge increases.
Answer:
Small sparks can lead to huge explosion if they are left unattended.
Explanation:
Small sparks are not harmful but if these sparks happen near some hazardous material or object then it could lead to heavy explosion. If there is some chemical substance near the spark or there are magnetic lines which can explode the spark then these minor sparks could result in heavy disastrous explosion.
Answer:
Explanation:
Given
mass of book(m)=2.1 kg
height up to which book is lifted is (h)2.2 m
height of person 
Potential energy of book relative to ground=mgh

(b)PE w.r.t to person head =mg(h-h0)

work done by person in lifting box 2.2 m w.r.t floor
Word done =Potential Energy of box relative to floor=45.2 J
Answer:
267.07 km
Explanation:
We have given the radius of the earth = 6378.1 km
In 2014 the difference between the magnetic north pole and geographical north pole is 2.40°
2.40°
We know that linear distance is given by 
So we have to travel 267.07 km in going from magnetic north pole to geographic north pole
Answer:
No.
Explanation:
Velocity is a vector quantity which means that it has a certain direction so things that move in different directions DO NOT have the same velocity.