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) mass.
Explanation:
The speed of a body is given by the relation between the displacement of a body in a given time. It can be considered the greatness that measures how fast a body moves.
Speed analysis is divided into two main topics: average speed and instantaneous speed. It is considered a vector quantity, that is, it has a module (numerical value), a direction (Ex .: vertical, horizontal) and a direction (Ex .: forward, upwards). However, for elementary problems, where there is displacement in only one direction, the so-called one-dimensional movement, it is advisable to treat it as a scalar quantity (with only numerical value).
The mass of an object is not an important factor in determining the speed of that object. However, time, direction and distance are important factors in determining speed.
Answer:
billion is larger \ part if billion
D, because C12 means there's 12 atoms of carbon.
Answer:
Moment=Force x Pivot
Explanation:
A moment is the turning effect of a force. Moments act about a point in a clockwise or anticlockwise direction.
Law of moments:
When an object is balanced (in equilibrium) the sum of the clockwise moments is equal to the sum of the anticlockwise moments.
How to calculate moments:
Moment=Force x Pivot