Answer:
(A) endothermic
(A) Yes, absorbed
Explanation:
Let's consider the following thermochemical equation.
2 Fe₂O₃(s) ⇒ 4 FeO(s) + O₂(g) ΔH = 560 kJ
Since ΔH > 0, the reaction is endothermic.
We can establish the following relations:
- 560 kJ are absorbed when 2 moles of Fe₂O₃ react.
- The molar mass of Fe₂O₃ is 160 g/mol.
Suppose 66.6 g of Fe₂O₃ react. The heat absorbed is:
The variable that stays the same in an experiment is called the controlled variable
Hope this helps
Answer:
Radiation
Explanation:
Thermal energy (heat) can be transferred between objects as long as there is a temperature difference between them. However, there needs to be some kind of medium transferring it. There are basically three ways in which the energy is transferred:
1. Conduction - transfer via the direct contact
2. Convection - transfer via the circular movement of fluids or air caused by hotter layers moving upward and colder downwards.
3. Radiation - transfer via the waves from the invisible spectrum of electromagnetic radiation ( ultra-violet, infra-red...)
Frequency is not a type of energy transfer, but a number of times something is occurring in one second. When we say that the frequency is 200Hz it means that something is happening at a rate of 200 times in a second. It's most often used in describing oscillations.
Higher, they have more energy so they move faster
