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3 years ago

According to the information in your study unit which of the following locations require the highest illuminance

1 answer:

7 0

The correct answer to this question is option D. A study area to the information in your study unit, the location that has to be the highest illuminance is the study room because it is the place the students can stay to study.

Hoped this helped :D

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In 1895, X-rays were accidentally discovered during a scientific experiment. Today, X-rays are used to screen luggage in airport

allsm [11]

Thanks for your question!

The answer is science influencing technology, as it was discovered in a science experiment. It doesn't really influence society as much because it doesn't influence the way people act, just the how things work.

Hope this helped!

4 0

3 years ago

If an atom has 12 protons 12 neutrons, and 12 electrons, what is the charge of the atom?

Evgesh-ka [11]

I think the charge is +2
Hope this helps

6 0

3 years ago

Which statements about fresh-water sources are true.? (Multiple Choice) (please help asap thanks!:)

Kay [80]

Answer:

The correct answers are:
"Only about 3 percent of Earth's water is fresh water."

"About 75% percent of the fresh water on Earth is frozen in ice sheets."

"The largest source of usable fresh water is groundwater."

Explanation:

3 percent of Earth's water is most certainly fresh water. Confirmed with a few fact checks.

The largest source of usable fresh water on Earth is groundwater. It's more difficult to access but it's there and much more usable than water say frozen in ice on the sea.

The most correct option left would be 75% of Earth's freshwater being in ice sheets even though it's about 70%.

3 0

2 years ago

Burning a compound of calcium, carbon, and nitrogen in oxygen in a combustion train generates calcium oxide , carbon dioxide , n

mylen [45]

The question is incomplete, here is the complete question:

Burning a compound of calcium, carbon, and nitrogen in oxygen in a combustion train generates calcium oxide (CaO), carbon dioxide $(CO_2)$ , nitrogen dioxide $(NO_2)$ , and no other substances. A small sample gives 2.389 g CaO, 1.876 g $CO_2$ , and 3.921 g $NO_2$ Determine the empirical formula of the compound.

Answer: The empirical formula for the given compound is $CaCN_2$

Explanation:

The chemical equation for the combustion of compound having calcium, carbon and nitrogen follows:

$Ca_xC_yN_z+O_2\rightarrow CaO+CO_2+NO_2$

where, 'x', 'y' and 'z' are the subscripts of calcium, carbon and nitrogen respectively.

We are given:

Mass of CaO = 2.389 g

Mass of $CO_2=1.876g$

Mass of $NO_2=3.921g$

We know that:

Molar mass of calcium oxide = 56 g/mol

Molar mass of carbon dioxide = 44 g/mol

Molar mass of nitrogen dioxide = 46 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 1.876 g of carbon dioxide, $\frac{12}{44}\times 1.876=0.5116g$ of carbon will be contained.

For calculating the mass of nitrogen:

In 46 g of nitrogen dioxide, 14 g of nitrogen is contained.

So, in 3.921 g of nitrogen dioxide, $\frac{14}{46}\times 3.921=1.193g$ of nitrogen will be contained.

For calculating the mass of calcium:

In 56 g of calcium oxide, 40 g of calcium is contained.

So, in 2.389 g of calcium oxide, $\frac{40}{56}\times 2.389=1.706g$ of calcium will be contained.

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Calcium = $\frac{\text{Given mass of Calcium}}{\text{Molar mass of Calcium}}=\frac{1.706g}{40g/mole}=0.0426moles$

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{0.5116g}{12g/mole}=0.0426moles$

Moles of Nitrogen = $\frac{\text{Given mass of Nitrogen}}{\text{Molar mass of Nitrogen}}=\frac{1.193g}{14g/mole}=0.0852moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.0426 moles.

For Calcium = $\frac{0.0426}{0.0426}=1$

For Carbon = $\frac{0.0426}{0.0426}=1$

For Nitrogen = $\frac{0.0852}{0.0426}=2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of Ca : C : N = 1 : 1 : 2

Hence, the empirical formula for the given compound is $CaCN_2$

3 0

3 years ago

What is the oxidation number of phosphorus (P) in phosphoric acid (H3PO4)?

Sedaia [141]

Hey there!:

H is always +1 so the H's have a +3 charge.

O is always -2 so the O's have a -8 charge .

Now, suppose oxidation state for P = X , then :

+3 + X + (-8) = 0 (because of neutral molecule)

x = 8 - 3

x = + 5

So, X = +5 oxidation state.

Answer C

Hope that helps!

4 0

3 years ago