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4 years ago

How many nonmetals are there on the periodic table?

Chemistry

2 answers:

ZanzabumX [31]4 years ago

4 0

There are 17 nonmetals

Hunter-Best [27]4 years ago

3 0

There are 17 nonmetals: <span>hydrogen, helium, carbon, nitrogen, oxygen, fluorine, neon, phosphorus, sulfur, chlorine, argon, selenium, bromine, krypton, iodine, xenon, and radon.</span>

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Consider the following reaction

aliina [53]

Answer:

d, 40 dm3.

Explanation:

According to Avogadro's law, the mole ratio of chemicals in a reaction is equal to the ratio of volumes of chemicals reacted (for gas).

From the equation, the mole ratio of N2 : H2 : NH3 = 1 : 3 : 2, meaning 1 mole of N2 reacts completely with 3 moles of H2 to give 2 moles of NH3, the ratio of volume required is also equal to 1 : 3 : 2.

Considering both N2 and H2 have 30dm3 of volume, but 1 mole of N2 reacts completely with 3 moles of H2, so we can see H2 is limiting while N2 is in excess. Using the ratio, we can deduce that 10dm3 equals to 1 in ratio (because 3 moles ratio = 30dm3).

With that being said, all H2 has reacted, meaning there's no volume of H2 left. 2 moles of NH3 is produced, meaning the volume of NH3 produced = 10 x 2 = 20 dm3. (using the ratio again)

1 mole of N2 has reacted, meaning from the 30dm3, only 10 dm3 has reacted. This also indicate that 20 dm3 of N2 has not been reacted.

So at the end, the mixture contains 20dm3 of NH3, and 20 dm3 of unreacted N2. Hence, the answer is d, 40 dm3.

7 0

3 years ago

Determine the number of atoms in 41.0 grams of calcium, Ca. (The mass of one mole of calcium is 40.08 g.)

Dovator [93]

Hi there!

Let me know if you have questions about my answer:

6.15 × 10²⁴

Explanation:

To find the number of atoms, divide the mass of calcium (m) by its molar mass (MM). This will give you the number of moles of calcium (n).

$n = m/MM$ Start with a formula

$=\frac{41.0g}{40.08g/mol}$ Substitute values from the question

$= \frac{41.0g*1mol}{40.08g}$ Simplify

$= \frac{41.0mol}{40.08}$ Cancel out the units "g"

$= 1.022...mol$ Number of moles of calcium, with 4 significant figures

Then, multiply the number of moles of calcium (n) by Avogadro's number ( $N_{A}$ ) to find the number of calcium atoms.

$Number.of.Ca=n*N_{A}$ Start with a formula

$= 1.022mol*\frac{6.022*10^{23}Ca}{1mol}$ Substitute values from the question

$= \frac{1.022mol*6.022*10^{23}Ca}{1mol}$ Simplify

$= 1.022*(6.022*10^{23}Ca)$ Cancel out the units "mol"

$= 6.154*10^{24} Ca$ Multiply, leave one extra digit to help round. "4" tells you to round down.

$= 6.15*10^{24} Ca$ Final answer to 3 significant figures*

*When multiplying and dividing numbers, your final answer will have the same number of significant figures as the number with the least number of significant figures in the question.

40.08 has 4 significant figures. 41.0 has 3 significant figures. So, you want 3 significant figures in your final answer.

I hope this helps!

Learn more about Avogadro's number here:

brainly.com/question/1445383

Check out another answer that uses significant figures:

brainly.com/question/3721164

7 0

3 years ago

Becquerel placed photographic paper in a drawer with some radioactive rocks and discovered that the amount of exposure on the pa

jolli1 [7]

Becquerel did not discover that the amount of exposure on the paper was proportional to the amount of uranium that was present in the rocks

<h3>What is radioactivity?</h3>

The phenomenon of radioactivity was discovered by the French scientist Henri Becquerel in 1896 when he placed photographic paper in a drawer with some radioactive rocks.

We have to note that Becquerel did not discover that the amount of exposure on the paper was proportional to the amount of uranium that was present in the rocks hence the stetement is false.

Learn more about radioactivity: brainly.com/question/1770619?

5 0

2 years ago

Jerod used a golf club to hit a ball what was the action and reaction

Triss [41]

The action was him hitting the ball the reaction was the ball moving after being hit

6 0

3 years ago

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Zac releases the air from a balloon. Which statement best describes what will happen to the air that was inside the balloon?

ad-work [718]

The correct answer is the last option. When <span>Zac releases the air from a balloon, it will expand to fill the room. It will not expand in the sense that molecules will be big but the molecules will be more spread out into the room and more air molecules will be present to fill the room.</span>

8 0

3 years ago

Read 2 more answers