Which is not a common property of ionic compounds? high melting point

good conductivity as a liquid

low melting point

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

Idon’t quite understand this problem

Which one of the following research methods can show cause and effect