<h3>
Answer:</h3>
915 Joules
<h3>
Explanation:</h3>
- The heat of fusion is the heat that is required to convert a given mass of a substance from solid state to liquid state without change in temperature.
- In this case, we are given specific heat of a substance as 122 joules per gram
- It means that amount of heat equivalent to 122 joules is required to change 1 gram of the substance from solid state to liquid state.
- Therefore, we can determine the amount of heat needed to change 7.5 grams of the substance from solid to liquid state.
1 g = 122 Joules
7.5 g = ?
= 122 × 7.5
= 915 Joules
Thus, 7.5 g of the substance at its melting point will require 915 Joules of heat to melt.
B. A solar cycle usually lasts 11 years.
The sun is made up of two main elements, hydrogen and helium.
- Hydrogen makes up about 92% of all of the atoms in the sun while helium makes up about 7.8%.
- Oxygen, carbon, neon and nitrogen make up most of the remaining 0.2%.
1. alpha particle
alpha particles are positively charged helium nuclei with weak penetrating power