Answer:
A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.
The general process for coal mining and refining is option C.
Coal mining is carried out by two main processes based on the depth, quality, thickness, and structure of coal seam. Based on the depth, coal seam of less than 180ft to the surface is surface mined while coal seems between 180ft.-300ft. are deep mined. The coal mined is transported to a nearby processing plant using a conveyor, train, ship, etc. where it is washed to remove other component like dirt, sulphur, rocks, etc. and afterwards dried.
Answer:
<em>It is a method used to identify a suspect.</em>
Explanation:
<em>DNA fingerprinting is a method used to identify an individual from a sample of DNA by looking at unique patterns in their DNA.</em>
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Depends on where the object is. On earth, moon , or somewhere without any other mass (theoretically). I think you mean how much does weigh on earth. So, the average gravitational acceleration on earth is : 9.83 m/s^2 To find out how much an object weighs, this is the formula : G=m.g where m is mass of the object g is the gravitational acceleration and G is weight. So, G = 10.9,83 = 98,3 N is the answer.
