Question:
How could you use a model to show the cause-and-effect relationship between Earth's rotation and the apparent motion of the stars across the night sky?
Answer:
Gravity? or density because of the pull from the sun.
<span>We can relate the average speed
of the gas molecules by its kinetic energy. The kinetic energy is the work done
by the object due to its motion. It is represented by the formula of the half
the velocity squared multiply by the mass of the object. The absolute zero
theory is the assumption that at 0 Kelvin or -273.15 degrees Celsius, the gas
molecules stop moving. It is because the temperature is severely cold enough to
allow movement of the gas molecules. The gas molecule that is closest to the
absolute zero is in cylinder B because it moves so slow and its movement is
almost near to the absolute zero theory.</span>
Answer:
Their digestive systems produce methane, a powerful
greenhouse gas
Answer:
Yes, a precipitate of PbS forms
Explanation:
The equation of the reaction is given as:
Pb(NO₃)₂ + Na₂S → PbS + 2NaNO₃
The lead sulfide forms a precipitate in the aqeous solution.
Precipitation is a form of reaction in which ions combines to form a solid precipiate. Most double displacement reactions in which ionic compounds are the reactants results in formation of a precipitate as the product.
There are rules of solubility which guides a reaction that would lead to the formation of a precipitate. The mos applicable of the rules to the reaction stated above is that "carbonates, phosphates, sulfides, oxides and hydroxides are insolube". The sulfide of lead formed in the product is therefore insoluble.
