Which of the following is true about a combustion reaction?

a. It is an endothermic reaction.

C. CO2 and H20 are produced.

b. Oxygen must be a reactant.

d. All of the above.

In order for organisms to stay alive and continue their species, they must overcome many challenges. Which of these is NOT one of the three challenges of life? Question 1 options: getting energy reproducing regenerating staying healthy

What two bodily functions are increased by a warm up

Eratosthenes used what object to determine the size of Earth? A) Pyramids in Giza, B) Tower in Babel, C) Sphinx in Alezandria, D) Well in Alexandria

The idea that one cannot forget something they've never learned is called A. pseudoforgetting B. repression C. amnesia D. dementia

Why does an object hover over a large magnet

An object is thrown upwards with the speed of 40.0 km/hr in 5 second, calculate the distance in millimeters (mm).

What controls the net direction of molecules?

Dispersion is the separation of white light into separate colors by A. differences in wavelength B. differences in wave amplitude C. the blocking of light D. constructive interference

Why would a person choose to tie a helium-filled balloon to a child's wrist instead of simply having the child hold on to it? A. Helium is less dense than air, so it will float above air if the child lets go of the balloon. B.

What process is the method by which a neutral object obtains an electrical charge?