In order for a reaction to begin, what is required?

activation energy

ionic bonding

precipitate forming

bubbling

Which of these questions about skateboarding can be answered using measurements? A. How much force is needed to break a skateboard? B. Why do people enjoy skateboarding? C. Which trick is the most popular? D.

Which sequence of moon phases is correct?. new moon, waxing crescent, full moon, waning gibbous first quarter, new moon, full moon, third quarter waning crescent, full moon, waxing crescent, new moon full moon, waxing crescent, waning crescent, new

Why is the law of gravity an example of a universal law? A) gravity is the attraction of any mass to any other other mass.

Description of the earths crust

During a double-slit experiment, you have the option of using either a green laser or a blue laser for your light source.

Why did scientists choose carbon as a base for the atomic mass unit? Which isotope of carbon did they use?

What organelle is found in all animal cells and some plant cells

Basic of Archimedes's principle of how fluid can make body to float and sink.

A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average force (in N) exerted on a 0.0500 kg bullet to accelerate it to a speed of 625 m/s in a time of 1.10 ms (milliseconds)

Your boss at the Cut-Rate Cuckoo Clock Company wants to save money on materials. You are asked to reduce the balance wheel, which is cylindrical, dimensions to one-third their original values.