Answer: <span>C) plasma
</span><span>
Natural phenomena characterized by colored lights in the sky, is caused by the interaction of charged particles of energy from the solar wind with the magnetic layer of the earth so we have turbulence and multicolored plasma clouds known as auroras arise.</span>
Tin metal reacts with hydrogen fluoride to produce tin(II) fluoride and hydrogen gas according to the following balanced equation.
Sn(s)+2HF(g)→SnF2(s)+H2(g)
Sn(s)+2HF(g)→
SnF
2
(s)+
H
2
(g)
How many moles of hydrogen fluoride are required to react completely with 75.0 g of tin?
Step 1: List the known quantities and plan the problem.
Known
given: 75.0 g Sn
molar mass of Sn = 118.69 g/mol
1 mol Sn = 2 mol HF (mole ratio)
Unknown
mol HF
Use the molar mass of Sn to convert the grams of Sn to moles. Then use the mole ratio to convert from mol Sn to mol HF. This will be done in a single two-step calculation.
g Sn → mol Sn → mol HF
Step 2: Solve.
75.0 g Sn×1 mol Sn118.69 g Sn×2 mol HF1 mol Sn=1.26 mol HF
75.0 g Sn×
1
mol Sn
118.69
g Sn
×
2
mol HF
1
mol Sn
=1.26 mol HF
Step 3: Think about your result.
The mass of tin is less than one mole, but the 1:2 ratio means that more than one mole of HF is required for the reaction. The answer has three significant figures because the given mass has three significant figures.
The answer to the question
stated above is:
<span> Gas is easily compressible because the molecules of a gas are much further apart than
those of a solid.</span>
characteristic properties of gases:
(1) they are easy to compress,
(2) they expand to fill their containers, and
(3) they occupy far more space than the liquids or solids
from which they form.
A straight line on a distance va time graph represents constant speed
2. <span>1/8 = (1/2)³ </span>
<span>so it's 3 half lives.</span>
