Answer:
D
Explanation:
Because the silk took away the electrons to allow the rod to become positive. They cant be destroyed because of the law of conservation of charges. Also protons cannot move only electrons can.
Answer:
The mass of the surrounding is 
Explanation:
From the question we are told that
The mass of
is 
The mass of water is 
The chemical equation for the dissociation process is

The specific heat capacity of the mixture is 
The combined mass of the solution is

The mass of the surround here is the mass of the coffee-cup calorimeter and this contain the mixture ( water and the NaOH ) so the mass of the surrounding is

Answer:
Air can be described as: Mass and Mixture of Gases
Mass is defined as how much stuff an object contains - and by stuff, I mean matter, like atoms and molecules. And even though you can't see it, air has a lot of atoms and molecules. Air is a gas (as opposed to a liquid or a solid) and contains about 78% nitrogen, 21% oxygen, and 1% argon.
Explanation:
Chlorophyll helps the plant by absorbing light energy and turning it into sugars to help the plant grow (photosynthesis)
The correct answer is A.