After completing 10 years of experimentation, a scientist reports a new scientific law about the movement of sand on beaches. how do you know that this information cannot be valid?

there are no previous laws to substantiate the information.

Explanation:

Scientific laws build upon each other. In other words, the laws complement each other. For instance, there are laws that are known as the fundamental laws. These laws lay down the foundation of all scientific beliefs and hypotheses. Without a satisfaction of these laws, the research will be null and void. In fact, it will be invalid unless the first principles of the physical laws are satisfied and proved.

the answer is   c.) 1575 j.

explanation:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%