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3 years ago

Whats the most common chemical element in the earths crust?

Chemistry

1 answer:

Alchen [17]3 years ago

5 0

Answer:

Oxygen

Explanation:

it is 47% of the earth's crust.the 2nd would be silicon if you wanted to know.

have a good day maam!

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Select the single best answer. Which mechanism properly shows the movement of electrons in the reaction? 2xsafari

sweet [91]

Answer:

Explanation:

We must study the reaction pictured in the question closely before we begin to attempt to answer the question.

Now, the reaction is a free radical reaction. This implies that only one electron is transferred. The transfer of one electron is shown using a half arrow rather than a full arrow. The both species are radicals (odd electron species) and contribute one electron each.

Hence we must show electron movements in both species using a half arrow.

5 0

3 years ago

Distinguish between sugar and non-sugar with examples.

kap26 [50]

Answer:

Reducing sugars are sugars where the anomeric carbon has an OH group attached that can reduce other compounds. Non-reducing sugars do not have an OH group attached to the anomeric carbon so they cannot reduce other compounds. ... Maltose and lactose are reducing sugars, while sucrose is a non-reducing sugar

3 0

3 years ago

Significant Digits and Scientific Notation Part 1: Determine the number of significant digits in each number and write out the s

MA_775_DIABLO [31]

Answer:

1. 6 significant digits. 2. 2 significant digits. 3. 8 significant digits. 4. 4 significant digits. 5. 8 significant digits. 6. 7 significant digits. 7. 2 significant digits.

Explanation:

All nonzero digits are significant. All zeros before nonzeros are insignificant. All zeros after nonzeros are insignificant unless they are made for precision of some data. So 405000 may have 3 or 6 significant figures. But usually all zero figures after significant digits are significant.

8 0

4 years ago

hich quantity describes how spread out a set of data is? O A. Standard deviation O B. Percent error O C. Line of best fit D. Mea

juin [17]

The answer to this is B.

6 0

4 years ago

At high temperatures phosphine (PH_3) dissociates into phosphorus and hydrogen by the following reaction: 4PH3 rightarrow P_4 +

Alex_Xolod [135]

Answer:a)p4=0.75mol

H2=4.5mol

B)PH3=1×10^7mole

P4=0.25×10^7mole

H2=1.5×10^7mole

Time taken for 3mol of phosphine to react is 54 ×10^7s

Explanation:From the balanced chemical equation

4PH3____P4+6H2

From Gay lussac law ,when gases combines

,They do so in a ratio which bear a simple ratio with their products,if gases.

So it means from the equation above

4 mol of PH3 will form 1mol of P4 and 6 mol of H2

Meaning that if 4mol of PH3 gives 1mol of P4

Then 3mol of PH3 will give 1/4 mol or 0.75 mol of P4 .

In the same vein,3mol of PH3 will give 6×3/4 mol of H2= 4.5 Mol of H2

B) molar concentration =mole/volume

Meaning mole=molar concentration ×volume

Molar concentration is given as 5Km/m^3=5000mol/m^3

Volume=2L =2×1000=2000m^3

Nos of moles=5000×2000=10^7moles

So for P4,nos of moles =1/4×10^7=0.25×10^7

ForH2 ,6/4 ×10^7=1.5×10^7 moles

Rate= volume/time

Time taken for reaction will be volume/rate=2000/3.715×10^6

=54×10^7s

5 0

3 years ago