Select each correct answer. More than one answer may be correct. Four atoms of hydrogen combine with one carbon atom to form CH4, but only two hydrogen atoms combine with one oxygen atom to form H2O. Which of the following helps to explain why?
Hydrogen has one valence electron.
Oxygen has two vacancies in its electron shell, but carbon has four vacancies.
Metallic bonds form between positively charged metal ions and delocalized electrons.
Atoms may share electrons in order to fill their electron shells.

A2000 kg car is rounding a curve of radius 200 m on a level road. the maximum frictional force the road can exert on the tires of the car is 4000 n. what is the highest speed at which the car can round the curve?

Acar is traveling 35 mph on a smooth surface . if a balanced force is applied to the car what happens?

You are the coordinator for a program that is going to take place at night in a rectangular amphitheater in the mountains. you will have no access to any electricity, but you must be able to illuminate the entire grounds. you know the intensity of the light from a lantern varies inversely as the square of the distance from the lantern. suppose the intensity is 90 when the distance is 5 m. a. write an equation to model the situation. b. solve for the constant of variation. c. write the equation to model the situation using the constant () of variation. d. you have been given lanterns with 40 light intensity. use your equation to solve for the distance from the lantern. e. you need to illuminate 225 km. how many meters do you need to light? f. how many lanterns will you need?