Answer:
Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal contains the energy stored by plants that lived hundreds of millions of years ago in swampy forests.
Answer: 21 lawns per week
Explanation:
The average weekly rate refers to how many lawns were mowed per week given that 233 were done in 11 weeks.
Rate will be given by;
= Lawns mowed / Weeks taken
= 233 / 11
= 21 lawns per week
A mixture is said to be homogeneous if its composition is uniform throughout the mixture. They are referred to as solutions. On the other hand, heterogeneous mixture does not have uniform composition. The substances present in the mixture have visible difference or phases.
Sea water is composed of salt, sand and water. Here, salt and water form homogeneous mixture but due to the presence of sand, the mixture is heterogeneous. Salt dissolves in water and the solution has uniform composition but sand does not dissolve in water, even after vigorous mixing, after some time it settles at the bottom resulting formation of layers. Thus, sea water containing salt, water and sand is a heterogeneous mixture.
Answer:
0.465
Explanation:
To find the volume of a substance, divide the mass by the density.
M/D = V
10.0 / 21.5 = 0.4651163
Then round to 3 significant figures: and the density is 0.465
They have low boiling points
