Atoms of element A decay to atoms of element B with a half-life of 20,000 years. If there are 10,000 atoms of A to begin with (and 0 atoms of B), how long will it take for there to be 2,500 atoms of A?

Witch one is right a) [J] = [ A^2 x Ω x s ] b) [J] = [ A x Ω x s ] c) [J] = [ A x Ω x s^2 ] d) [J] = [ A^2 x Ω^2 x s^2 ]

A plane heads due north at an airspeed of 180 km/h. the wind is blowing from the west at 60km/h. what is the planeâs velocity with respect to the ground? a190 km/h b480 km/h c240 km/h d120 km/h

Only electrons orbit the nucleus of an atom true or false

Physical property of Aluminum foil can be gray color

What are the first 36 elememts in the periodic table

A gate in an irrigation canal is constructed in the form of a trapezoid 2 m wide at the bottom, 38 m wide at the top, and 2 m high. It is placed vertically in the canal so that the water just covers the gate.

A machine with a mechanical advantage of 10 is used to produce an output force of 250 newtons. What input force is applied to this machine

Why do you float in space

How does physical change affect the identity of a substance

A scientist pours grape juice on three identical white shirts He then uses three different cleaning products on the shirts and measures how clean they get what is the independent variable in this experiment