Answer with Explanation:
A candle relights when a match is held above the wick because its trail of smoke still contains some of the wax. When candles are burned, the heat of the flame turns the the wax (which is originally solid) into liquid (commonly near the wick) and then evaporates as gas. The vaporized wax actually protect the wick and this is the reason why it is not burned. So, when you put off a candle, the vaporized wax is still present near the wick. This, remember, holds heat and light energy. Thus, this explains why the candle can be relighted once you hold a match above the wick. It then allows the match to ignite.
Thus, this explains the answer.
<span>6s²4f¹⁴5d¹⁰6p²
6 shows that the element is in the 6 period,
6p² shows that the element is in the 14th group. (1 and 2 groups have s -electrons as last ones, 13 group has s²p¹, and 14 group has s²p²)
The element is Pb.
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Answer:
Explanation:
The element V forms acidic oxide so it must be non- metal because oxides of non metal forms acidic oxide like sulphur ( s ) or chlorine ( Cl₂ )
sulphur forms SO₂ or SO₃ . Chlorine forms acidic oxide like Cl₂O₇ , Cl₂O₃ etc
These oxides are covalent compounds .
So V may have 6 or 7 electrons in the outermost orbit .
Hence option D is the right answer.
Answer:
See explanation.
Explanation:
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In this case, since we know the heat of reaction per gram of reactant and we should know the total energy of reaction, but it is not there, we are going to assume it is 1200 J as usual in these problems, so you can change it to whatever your given heat is.
In such a way, we set up the math as shown below:
Which results:
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The molecular weight of water is <span>18.01528 g/mol.
So in 2.92 grams there are 2.92/</span>18.01528 = 0.1621 mol of particles.
1 mol contains 6,02214 × 10^<span>23 particles by definition.
So the nr of H2O molecules is </span>0.1621 * 6,02214 × 10^23 = 0,9761 × 10^23.
Every molecule has 2 H atoms, so you have to double that.
2* 0,9761 × 10^23 = 1.952 × 10^23.
