Least dense means the one that is at the top. Wood floats on top of water, so wood would be the least dense. Water has a density of 1 and the others would all sink, so they're more dense. The answer is wood
the answer is true the first one
Answer:
Below.
Explanation:
Coal gas is a mixture of a variety of gases: inflammable gases including, hydrogen, methane, ethylene, carbon monoxide and volatile hydrocarbons and small amounts of non flammable gases like nitrogen and carbon dioxide.
Water gas consists mainly of carbon monoxide and hydrogen.
Producer gas is similar to water gas and consists mainly of carbon monoxide and hydrogen together with nitrogen and carbon dioxide.
Natural gas occurs naturally and consists mainly of methane with small amounts of other hydrocarbon gases.
Answer:

Explanation:
The pressure, the volume and the temperature of an ideal gas are related to each other by the equation of state:

where
p is the pressure of the gas
V is the volume of the gas
n is the number of moles
R is the gas constant
T is the absolute temperature
For the gas in this problem:
n = 2.00 mol is the number of moles
V = 17.4 L is the gas volume
p = 3.00 atm is the gas pressure
is the absolute temperature
Solving for R, we find the gas constant:

A.
Weldings sparks could start fire on wood.
Lightning can ignite a fire one a tall tree
Open flames can start another fire if made in contact especially with flammable substances