pH stands for
the power of hydrogen. pH that ranges form 1-6.9 are acid substances. At pH 1 -
2.9, the substance is highly acidic which will have the color from red to red - orange. At pH 3 - 4, the substance is mildly
acidic and the color range is from red - orange to orange. At pH 4.1 – 6.9, the substance is weakly acidic and the color range is from orange to yellow. At pH 7, it is
neutral and it is green in color. At pH 7.1-14, it is basic. At pH 7.1 - 10.9, the substance is weakly
basic the color range is from green to blue. At pH 11 - 13, the substance is mildly basic and the color range is from blue to purple. At pH 13.1 – 14, the
substance is highly basic and the color range is from purple to light purple.
Answer: light and heat
Explanation:Our sun is the source of all life on Earth, and solar energy is useful to us in many different ways. The sun creates two main types of energy - light and heat - that we can harness for many activities ranging from photosynthesis in plants to creating electricity with photovoltaic (PV) cells to heating water and food.
Answer:
Blue dye spreads out quicker
Explanation:
This is because the dye gets spread out by water molecules. Warm water has faster moving water molecules than cold water.
Answer: The correct option is (c). The total pressure doubles.
Solution:
Initially, only 4 moles of oxygen gas were present in the flask.
(
) ( according to Dalton's law of partial pressure)
....(1)
= Total pressure when only oxygen gas was present.
Final total pressure when 4 moles of helium gas were added:

partial pressure of oxygen in the mixture :
Since, the number of moles of oxygen remains the same, the partial pressure of oxygen will also remain the same in the mixture.

= Total pressure of the mixture.
from (1)

On rearranging, we get:

The new total pressure will be twice of initial total pressure.
Answer:
when water changes from a liquid on earths surface to a gas in the atmosphere,this is known as evaporation