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:
22 mol
Explanation:
Given data:
Number of atoms of Cl = 2.65×10²⁵ atom
Number of moles of Cl = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.65×10²⁵ atom × 1 mol / 6.022 × 10²³ atoms
0.44×10² mol
22 mol
scandium is a transition metal and shows a valency of 3.
Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out possible to set up the following energy equation for both objects 1 and 2:

In terms of mass, specific heat and temperature change is:

Now, solve for the final temperature, as follows:

Then, plug in the masses, specific heat and temperatures to obtain:

Yet, the values do not seem to have been given correctly in the problem, so it'll be convenient for you to recheck them.
Regards!
Answer:
Anything that can be done to increase the frequency of those collisions and/or to give those collisions more energy will increase the rate of dissolving.
Explanation:
depended on the temperature