Answer:
Explanation:
To separate the a mixture of chalk and potassium chloride, we must not that chalk is calcium carbonate compound, CaCO₃.
Calcium carbonate has low solubility in water. KCl is readily soluble in water and it is also an ionic compound.
To separate a mixture of compounds with various solubility, we can carryout dissolution, filtration and evaporation.
We first pour pure water into the mixture. Water will dissolve the potassium chloride readily.
Then using a filter paper we filter out the suspended chalk particles. Leave the filtrate to then dry and collect it.
The solution filtered should be evaporated to dryness. This will leave the KCl behind from the solution.
Answer : Malik's experiment included to create artificial atmospheric oxygen; in order to perform experiment on red-legged grasshopper for growing it larger than normal, the part of recreating or mimicking the artificial oxygen for the experiment with additional 10% increase seems to be bit difficult and this may create a problem in defining the accuracy and precision for the experiment.
2.a) warm air is lighter than cold air so thats why it's warmer upstairs than downstairs
3.d) Conduction<span> is the process by which heat energy is transmitted through contact with neighboring molecules</span>
4.d) the lamp radiates heat throughout the plants
Answer:
Option C is the correct. Valence electrons have a higher energy level than those in other filled shells
Explanation:
Electrons must lose energy to move from the first to the second shell. FALSE
The electrons always win energy to move from the first to the second shell.
All the electrons in an atom have similar energy levels FALSE.
They are not neccesary similar. In hydrogen these are the level energy -13.6 eV
, -3.4 eV
, -1.51 eV
, -85 eV and -54 eV
Electrons do not have potential energy, just kinetic energy. FALSE
They have both.
Valencia electrons are the last electrons in the last layer. They have as much energy as possible and are responsible for forming bonds with other elements.
Answer:
A. All organisms need water as energy source