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3 years ago

Identify the f-block element.

Chemistry

1 answer:

GaryK [48]3 years ago

3 0

Answer: E. none of these

Explanation: because the f-block element is n-2

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Please answer!

evablogger [386]

1.) A compound is a substance that originates from two or more separate elements. It shares some similarities with a mixture.

2.) A compound has quite different properties from which it was formed. It also cannot be separated easily. Compounds are formed by chemical reactions.

3.) A pure substance has a constant composition and has consistent properties. It can be a compound or an element, but its composition is constant.

Hope this helps. :)

5 0

3 years ago

__________ solutions are very unstable.

Serhud [2]

Answer:

none of the above

Explanation:

because all of them are unstable

3 0

3 years ago

Read 2 more answers

Considering that the mantle is 44.8% oxygen and 21.5% silicon by mass, calculate the mole ratio of oxygen atoms to silicon atoms

horrorfan [7]

The mantle has a mass of around $4.278 X 10 ^2^4 kg$ that is around 68.4% of earth's mass.

So to calculate moles we need to first find out the mass of oxygen and silicon present in mantle. It is given that oxygen is 44.8% by mass in mantle and 21.5% by mass in mantle, therefore to calculate its mass, we need to use $\text{mass percentage }=\frac{\text{mole of solute}}{\text{mass of solution}}\times100$

Now, to calculate mass percentage of oxygen

$44.8 =\frac{x}{4.278X10^2^4kg}\times100$

$x= 191.65\times10^2^2kg$

Similarly the mass of silicon can be calculated

$21.5 =\frac{x}{4.278X10^2^4kg}\times100$

$x=91.977\times10^2^2kg$

Now, the moles of any substance is calculated by

$\text{moles}= \frac{\text{given mass}}{\text{molar mass}}$

$\text{moles of oxygen}= \frac{191.65\times10^2^2kg}{2.6566962\times10^-^2^6kg}$

where, mass of oxygen in kilograms is $2.6566962\times10^-^2^6kg$

So, $\text{moles of oxygen}=72.1384\times10^4^8\text{moles of O}$

Similarly $\text{moles of silicon}= \frac{91.977\times10^2^2kg}{4.663\times10^-^2^6kg}$

$\text{moles of silicon}=19.724\times10^4^8\text{moles of Si}$

Now, to calculate mole ratio we need to divide every moles to the lowest calculated mole that is the moles of Si and round it off to the nearest whole number.

$\text{mole ratio of oxygen}= \frac{72.138\times10^4^8kg}{19.724\times10^4^8kg}$

$=3.65\approx 4$

$\text{mole ratio of Silicon}=\frac{19.724\times10^4^8}{19.724\times10^4^8}$

$=1$

$\text{Mole ratio of Oxygen : Mole ratio of Silicon} = 4:1$

6 0

4 years ago

Read 2 more answers

Which of the following represents an inorganic compound? A. C6H12O6 B. C2H4O C. C2H5NO2 D. FeSO4

STALIN [3.7K]

In organic compounds<span>, any atom that is not carbon or hydrogen is called a/an____. The abbreviation"R" in a chemical formula </span>represents<span> a functional group or a hydrocarbon portion of the molecule. i hoped that helped alittle</span>

5 0

3 years ago

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How many liters are in 20 grams of hydrogen gas?

motikmotik

$\huge\bold{\mathfrak{\purple{A{\pink {n {\green {s{\blue{w{\red{e {\orange {r}}}}}}}}}}}}}$

Volume of 20 g of hydrogen at normal temperature and pressure (NTP) = 240.55 ml.

$\huge\sf\underline{\underline{\red{❥︎ Thanks}}}$

3 0

3 years ago