The efficiency is the number of times a machine multiplies the input force

true or false

1. what type of power generation can cause air pollution A. wind B. Natural Gas C. Geothermal D. Solar 2. Which fossil fuel produces the least carbon dioxide A. Coal B. Natural Gas C. Oil D. Nuclear Energy 3.

A piece of silver metal has a mass of 3.687 grams. If the density of silver is 10.5 g/cm, what is the volume of the silver?

A balloon is first filled with 4.00 moles of hydrogen. then, 2.00 moles of oxygen are added. if the volume was initially 21 l when just the hydrogen was present, what is the volume after the oxygen is added?

Using the information listed in Figure 2-1 what is the pH of the strongest base?

Which statement best defines specific heat? A. The amount of heat required to increase the temperature of 1 mol of a substance by 1 °C. B. The amount of heat required to increase the temperature of 1 L of a substance by 1 °C. C.

What does H2 stand for

How the model of an atom has changed over time because?

Which of the following conditions indicate a basic solution at 25°C? a. POH=11.21 b. pH=9.42 c. [OH-]>[H+] d. [OH]> 1.0 x 10^-7 M

A change in the properties of matter that does not change the identity of the substance is a chemical change a physical change an ionic change a covalent change

5. Express the composition of each atom in shorthand form. a. zinc-64 b. chlorine-37 c. hydrogen-3 d. calcium-40