Fluorite can scratch a copper coin but cannot be scratched by a copper coin.
This is because according to Mohs scale of hardness, fluorite has a hardness of four. Copper has a hardness of three. Therefore fluorite is a harder mineral than copper and will scratch copper but it will not be scratched by copper.
Mohs based his scale on the fact that some minerals could scratch others. If one mineral could scratch another but could not be scratched by it, he reasoned that it must be harder.
Answer:
Why is "sunlight" written above the arrow in the equation, rather than on the either side of it?
Sunlight is neither a raw material nor a product of the reaction, and is the energy source for the reaction.
Answer:
Vascular system - phloem and xylem
Explanation:
The phloem is responsible for translocating nutrient and sugars which are produced by the leaves to areas og the plant that are metabolically activew while the xylem cell wall transport water gom the root to the leaves.
However, a plant may have many xylem tissues extending up to the plant.
Answer:
frequency of the blue (B) allele 
frequency of the red (R) allele 
The number of blue plants expected is 
The number of red plants expected is 
The anticipated number of violet plants is 
Calculated chi square value
Explanation:
Frequency of blue allele is
Frequency of blue allele is equal to sum of frequency of BB and half of frequency of BR
Frequency of other allele
Chi Square test
See the attached file
The number of blue plants expected is
The number of red plants expected is
The anticipated number of violet plants is
Calculated chi square value
