Answer:

Explanation:
Given that,
Initial force, 
distance, d = 2 m
New distance, d' = 4 m
We need to find the new force. The electrostatic force between two charges is given by :

So,

So, the new force is equal to
.
The mass of Actinium 227 left is 0.0078 kg
Explanation:
The amount of mass left of a radioactive isotope after time t is given by the equation:

where
is the initial amount of the sample
t is the time
is the half-life of the isotope
For the sample of Actinium 227 in this problem,


t = 160 years
Substituting into the equation,

#LearnwithBrainly
The technical name for super glue type adhesive is Cyanoacrylate glue
Answer:
the answer is D
Explanation:
if you read the paragraph and question number 4 it tells you the answer wich is d