Thermal energy, or heat, is the internal energy in substances; it is the vibration and movement of the atoms and molecules within a substance. The more thermal energy in a substance, the faster the atoms and molecules vibrate and move. Geothermal energy is an example of thermal energy.
Answer:
Explanation:According to the law of conservation of mass (mass remains the same throughout a reaction), mass is conserved in this case. This can be proven by comparing the weight of two enclosed glass containers of the reaction. They will most likely have the same weight because the products the chemical reaction creates would most likely produce a gas that can be trapped if there is no opening in the glass container. To further investigate, compare the weights of the products of the reaction with an enclosed container to another container with no lid of the same reaction.
Answer: The child isotope has an atomic mass of 206.
Explanation:
Alpha decay : When a larger nuclei decays into smaller nuclei by releasing alpha particle. In this process, the mass number and atomic number is reduced by 4 and 2 units respectively.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
