In order for a combustion reaction to occur, like the burning of fossil fuels, what element is required?

Sulfur

Hydrogen

Oxygen

Helium

Why is there always some waste heat in a heat engine?

The electricity went out at José's home, and he lit some candles until the lights came back on. The candle wax near the wick became soft right away, and melted over a temperature range. Which term best applies to the candle wax? A. amorphous solid B.

A sample of argon gas (molar mass 40 g) is at four times the absolute temperature of a sample of hydrogen gas (molar mass 2 g). the ratio of the rms speed of the argon molecules to that of the hydrogen is

A steel wire in a piano has a length of 0.600 m and a mass of 5.200 ✕ 10-3 kg. To what tension must this wire be stretched so that the fundamental vibration corresponds to middle C (fC = 261.6 Hz on the chromatic musical scale) ?

An inventor claims to have built a machine that can produce 120j of work with and input of 110j of work. would you believe the inventors claim?

Why should scientists write reports and give oral presentations of the steps and results of their in investigations?

Which of these rocks are formed by volcanic activity? select the two correct answers. a. marble b. basalt c. limestone d. granite e. sandstone

Which source is most likely an authority on the subject? Dr. Vale, a pediatrician, discusses electrical circuitry on her home-improvement website. Jonah, an amateur cook, teaches his son how to make the best grilled cheese sandwiches.

What methods can be used to break down substances into elements

8. A gas is contained in a horizontal piston-cylinder apparatus at a pressure of 350 kPa and a volume of 0.02 m3. Determine the work done by the piston on the gas if the cylinder volume is increased to 0.15 m3 through heating.