The sun is the primary source of light. Other artificial sources are light bulb, torch light and some others. Thats all i can think of.
A reaction between two pure solids is very rare. For a reaction to occur, the molecules must interact with each other. Since molecules of solids are very compact, they don't have the liberty to collide with one another. However, this is made possible by hydrates of solids. An examples would be CuSO₄·5H₂O. In this case, they have a an intermediate liquid to react them together.
Answer:
I don't know I'm sorry I will tell you another answer asks me
The object is moving at a constant speed and towards the point of origin.
<h3>What is the distance time graph?</h3>
The distance time graph is used to show the relationship between the distance covered and the time taken. We know that the slope of the distance time graph is known as the speed of the object.
Given the fact that uniform or constant speed occurs when the distance is changing by equal amounts in equal time intervals, it is clear that is we have a straight line graph, the object is moving at a constant speed.
A good look at the graph as shown implies that the object is moving at a constant speed and towards the point of origin.
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