Answer:
M₂ = 1.9 M
Explanation:
Given data;
Volume of sodium chloride = 200 mL
Molarity of sodium chloride = 4.98 M
Volume of water = 532 mL
Final Molarity = ?
Solution:
M₁V₁ = M₂V₂
M₂ = M₁V₁ /V₂
M₂ = 4.98 M × 200 mL / 532 mL
M₂ = 996 mL. M /532 mL
M₂ = 1.9 M
Answer:
=> The colour of this stone is usually a pale greenish blue, owing to the presence of iron impurities. Stones that are treated with heat look more blue than green. On the Mohs scale of hardness, aquamarine ranges between 7.5 and 8 making it a relatively hard gemstone.
=> The best way to identify a real aquamarine stone is by looking at its colour. In its natural form, they have a pale blue colour, which is similar to seawater. They may have a slight green or yellow tint as well. Naturally occurring gems have excellent clarity and transparency.
=> The hardness of the stone is another feature you can use to identify the stone. Aquamarine stones are hard and they don’t get scratches easily. However, they can easily scratch glass and other such surfaces. So, if you find visible scratches on the stone, rethink your decision to buy it.
=> Most faceted aquamarine stones are clean to the eye and clear of any inclusions. However, translucent and opaque aquamarine is also available. These are usually fashioned into cabochons or beads. In some cases, inclusions may appear as parallel tubes. Such stones can be crafted to show a cat’s eye. Stones with cat’s eye and star effect are rare and highly priced.
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:)
Answer:
Henry Moseley
Explanation:
Dmitry Mendeleef and Lothar Meyer proposed a periodic table based on the atomic mass.
They stated a periodic law expressed as "chemical properties of elements are a periodic function of their atomic weights".
But, Henry Moseley in 1900s re-stated periodic law by changing the basis of the law from atomic weight to atomic number.
The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".
