What is the angular velocity of a wheel that rotates 2 and a half in 2.5 seconds? A) π / 8 rad
B) π / 4 rad
C) 2π rad
D) π rad

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.

How do you know how many valence electrons an atom has?