Answer:
option D.
Explanation:
The correct answer is option D.
Diffusion is the particle movement from high concentration to low concentration, such as air, water, etc.
Example: if you spray perfume spread throughout the room at one part of the fragrance scent.
The gas molecule thus spreads out in a gradient of concentration
When liquid cools, both its density and volume increases. Therefore the answer to your question are #s 1 and 5. This is due to the fact that molecules which are compacted or pressed against each other form a solid, and when they start to cool-down the molecules start to break free from each other increasing the density of a liquid and the space that it occupies.
Explanation:
It isn't possible to learn an entire language fast. For an examination, memorise some of the easy words. Practice mew minutes speaking French and keep speaking it till you know it.
Answer:
After 80 years there will be 3 g of element X remaining
Explanation:
Given;
the half life of element X = 20 year
initial mass of element X = 48 g
a) How much is there after 80 years
0 year --------------------------> 48 g
20 years -----------------------> (48g / 2) = 24 g
40 years ------------------------> 12 g
60 years ------------------------> 6 g
80 years --------------------------> 3 g
Therefore, after 80 years there will be 3 g of element X remaining.
