Answer:
<em><u>700N</u></em>
Explanation:
<em><u>F</u></em><em><u>=</u></em><em><u>ma</u></em>
<em><u>mass</u></em><em><u>=</u></em><em><u>35</u></em>
<em><u>acceleration</u></em><em><u> </u></em><em><u>=</u></em><em><u>20</u></em>
The Bohr Model, which was proposed by Niels Bohr in 1913
Pure substances can or can not be chemically combined.
Pure substances can be either elements or compounds, but not mixture. Mixture are different substances mixing together without being chemically combined, such as air, which is a mixture of oxygen, carbon dioxide, water etc. Mixture can be separated by physical methods, like filtration or decantation.
Meanwhile, elements are the substances that cannot be further separated by any means. No matter physical or chemical methods. Examples of elements are oxygen, hydrogen, neon and all the other ones from the periodic table. Compounds are basically elements joining together, but they’re chemically combined which means their electrons (kind of subatomic particle) are either shared or given away. These elements can only be separated by chemical methods like electrolysis or heating.
Therefore, as long as the substance cannot be separated by physical methods, it can be considered as a pure substance. We can now conclude that pure substance can be (element) or can not be (compound) chemically combined.
Answer to this is O-atom.
Explanation: The Bronsted acid-base theory is the backbone of chemistry. This theory focuses mainly on acids and bases acting as proton donors or proton acceptors.
where 
is the Lewis Acid and 
is the Lewis Base and 
is the Covalent Bond.
Reaction of dissociation of 
in 
is given as:
In this reaction O-atom has lone pair in water and therefore it accepts the proton from 
forming a Lewis Base.
Answer:
C
Explanation:
okay, you need to look at the structures of the particles of matter in the solid, liquid and gas.
- particles in a solid are in fixed positions, where they can only vibrate in those positions ( take a look at ice, or rather, a brick)
- liquids have very small or rather, no spaces between them, but they can slide or rub against each other, like people in a <em>really tight</em> crowd I guess
- gas particles have very large spaces between them and they move randomly. these exibit what's called brownian motion.
- since water particles (and all other liquid particles) have negligible spacings and limited movement, that allows the dye particles to move from a region of high concentration to that of a low concentration. the aim for this is for the mixture/solution to reach an equilibrium, that is the mixture must get to a point where all regions have the same concentration of the dye.
you can refer to your coursebooks :)
correct where wrong please:)
