Answer:
1.82 L
Explanation:
We are given the following information;
- Initial volume as 2.0 L
- Initial temperature as 60.0°C
- New volume as 30.0 °C
We are required to determine the new volume;
From Charles's law;

Where,
are initial and new volume respectively, while
are initial and new temperatures respectively;



Rearranging the formula;


Therefore, the new volume that would be occupied by the gas is 1.82 L
I believe the correct answer from the choices listed above is the second option. The expression (6.0 x 104) (3.1 x 10-1) is equal to 1.9 x 10^4. We only have two significant figures from the starting expression that is why we rounded of the product from 1.86 to 1.9.
<u>Answer:</u> The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g
<u>Explanation:</u>
We are given a function that calculates the amount of sample remaining after 't' years, which is:

Putting values in above equation:


Hence, the amount of sample left after 20 years is 288.522 g
Putting values in above equation:


Hence, the amount of sample left after 50 years is 144.26 g
The correct option is B.
Mendeleev was the one who originated the idea of arranging elements in the periodic table according to their chemical and physical properties. He left spaces in the periodic table and predicted the discovery of those elements that had not been discovered then. One of these elements is Gallium. He predicted that gallium is going to be a metal and he gave the properties that the element will possess. He also predicted that the element gallium will be placed under aluminium in the periodic table.