1 give reason
A. melting of snow can both be a desirable and undesirable change
b. appearance of hailey comet once every 72 year is a periodic change

Estimate the schwarzschild radius (in kilometers) for a mini-black hole formed when a superadvanced civilization decides to punish you (unfairly) by squeezing you until you become so small that you disappear inside your own event horizon. (assume that the your weight is 50 kg)

Can you match these to the correct definition

What type of force holds atoms together in a crystal?