As one goes from left to right in a period, which of the following is true?

A. The number of protons decreases.

B. The number of valence electrons increases.

C. both A and B

D. none of the above

A box is at rest with respect to the surface of a flatbed truck. the coefficient of static friction between the box and the surface is μs.

Is sodium oxide a compound or element?

A person is able to pull a rope with a force of 700 N. What is the minimum number of fixed and moveable pulleys that the person will require to lift up a 27,800 N elephant?

a volleyball player hit the ball with a mass of 0.25 kg. The average acceleration of the ball is 15.5 m/s2. How much force did the volleyball player apply to the ball?

A motor has a rating power of 20 W and motor is used for 10 s. Calculate the energy supplied to the motor.

During a medical condition screening lung capacity testing is a standard procedure. True of false

Which of the following is a unit of energy found in food? a). vitamin b) calorie c) nutrient d) water

As one goes from left to right in a period, which of the following is true? A. The number of protons decreases. B. The number of valence electrons increases. C. both A and B D. none of the above

Which of the following surfaces reflects the most light A yellow cloth B. tree trunk C aluminum foil D. Concrete sidewalk

Which part of an atom has a mass approximately equal to 1/2000 of the mass of a common hydrogen atom? A. nucleus B. electron C. proton D. electron cloud