Answer:
Galileo discovered that objects that are more dense, or have more mass, fall at a faster rate than less dense objects, due to this air resistance. A feather and a rubber ball dropped together. Air resistance causes the feather to fall more slowly, while the ball falls more fast.
Reaction of Cu(NO₃)₂ with each salt is as follow,
1) with KNO₃;
Cu(NO₃)₂ + KNO₃ → Cu(NO₃)₂ + KNO₃
Both salt products are water soluble.
2) With CuSO₄;
Cu(NO₃)₂ + CuSO₄ → CuSO₄ + Cu(NO₃)₂
Again both Salt products are water soluble.
3) With K₂SO₄;
Cu(NO₃)₂ + K₂SO₄ → CuSO₄ + 2 KNO₃
Again both salt products are water soluble.
4) With K₂S;
Cu(NO₃)₂ + K₂S → CuS + 2 KNO₃
In this case CuS is water insoluble, hence precipitates out.
Result:
Option-4 is the correct answer.
Answer:
The person should not be concerned about radon.
Explanation:
<em>A person living on the sixth floor of an aparment probably should not be concerned about radon</em>. In the conditions of the Earth's atmosphere (temperature and pressure), radon exists as a gas. This gas has a density that is approximately 8 times higher than the density of air (9.73 g/L compared to 1.22 g/L). <em>This means that radon gas would not rise, and instead remain close to the ground</em>, meaning that an apartment on a sixth floor is too far away from the ground for radon gas to reach there.
A gas being denser than air is also the reason why if you blow into a balloon, it will fall to the ground, because CO₂ is denser than air.
Answer:
Modern periodic law
Explanation:
There are many ways of stating the modern periodic law. Generally, the modern periodic law states that the properties of elements are a periodic function of their atomic numbers. That means, similar properties recur periodically when elements are arranged according to increasing atomic number.
Two scientists were largely responsible for our present day understanding of the modern periodic law, they are, Mendeleev and Moseley. Their work laid the foundation for the periodic table in its current form.
Answer:
mL
Explanation:
Atmospheres (atn), Torr, and mm of Hg are all units of pressure but mL is a unit of volume, not pressure.
