Answer:

Explanation:
We already know that the mass number of an atom is the sum of the number of protons and the number of neutrons.
So, the mass number of this isotope is;
Number of protons = 7
Number of neutrons = 8
Mass number = 7 + 8 = 15
Hence, the isotope is;

Answer:
heat; temperature; surrounding; insulated.
Explanation:
A calorimeter can be defined as a scientific instrument (device) that is designed and developed for measurement of the heat involved in chemical reactions or other processes, especially by taking the measurement of the temperature of the materials surrounding the process.
Basically, a calorimeter is insulated using materials with a very high level of resistivity, so as to prevent heat transfer to the outside of the device (calorimeter).
Some of the components that make up a simple calorimeter are; thermometer, an interior styrofoam cup, an exterior styrofoam cup, cover, etc.
Additionally, a calorie refers to the amount of heat required to raise the temperature of a gram of water by one degree Celsius (°C)
Answer:
F
Explanation:
A carousel can be made to rotate using different sources of energy. One may decide to use electric energy, manual effort, water energy or heat energy as in a candle carousel.
When the candle is lit, heat energy is supplied and warm air rises heating up the air near the carousel eventually causing it to start rotating.
Hence heat from the candle leads to a current of warm air that rises up, causing the carousel to start rotating.
For any given element the mass number can be found by adding the protons and the neutrons.
In this case its 10 protons plus 11 neutrons which gives us 21 as the mass number.
Answer:
fossil fuels are cost-effective.