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zzz [600]
3 years ago
13

Scientific knowledge results from the interaction of scientists who are investigating natural phenomena. Which of these BEST des

cribes how a scientific explanation becomes widely accepted?
Group of answer choices

DNA is not necessary for an organism to reproduce.

Organisms create their own DNA sequence that is not like their parents.

. DNA contains genes that hold specific traits for an organism.

A. DNA is an exact copy from parent to offspring.
Chemistry
1 answer:
seraphim [82]3 years ago
6 0

Answer:

5ywhxhghghghfhffgffgffg

Explanation:

You might be interested in
Part IV. Limiting Reactants! A Challenge Problem!
Alexxandr [17]

Answer:

a. Fe2O3(s) + 2Al(s) → 2Fe(s) + Al2O3(s)

b. Fe2O3 is the limiting reactant.

c. 6.30 grams Fe

d. 52.6 %

Explanation:

Step 1: Data given

Mass of iron(III) oxide Fe2O3 = 9.00 grams

Mass of aluminium = 4.00 grams

Molar mass Fe2O3 = 159.69 g/mol

Aluminium molar mass = 26.98 g/mol

Step 2: The balanced equation

Fe2O3(s) + 2Al(s) → 2Fe(s) + Al2O3(s)

Step 3; Calculate Moles

Moles = mass / molar mass

Moles Fe2O3 = 9.00 grams / 159.69 g/mol

Moles Fe2O3 = 0.0564 moles

Moles Al = 4.00 grams / 26.98 g/mol

Moles Al = 0.148 moles

Step 4: Calculate limiting reactant

For 1 mol Fe2O3 we need 2 moles Al to produce 2 moles Fe and 1 mol Al2O3

Fe2O3 is the limiting reactant. It will completely be consumed (0.0564 moles).  Al is in excess. There will react 0.0564*2 = 0.1128 moles

There will remain 0.148 - 0.1128 = 0.0352 moles Al

Step 5: Calculate moles Fe

For 1 mol Fe2O3 we need 2 moles Al to produce 2 moles Fe and 1 mol Al2O3

For 0.0564 moles Fe2O3 we'll have 2*0.0564 = 0.1128 moles Fe

Step 6: Mass of Fe

Mass Fe = 0.1128 moles * 55.845 g/mol

Mass Fe = 6.30 grams

Step 7: If you carried out this reaction and it actually produced 0.475 mL of molten iron (r = 6.98 g/mL), what is the percent yield of this reaction?

Density = mass / volume

Mass = density * volume

Mass = 6.98 g/mL * 0.475 mL

Mass = 3.3155 grams

Percent yield = (actual mass / theoretical mass) * 100%

Percent yield = (3.3155 /6.30 ) * 100 %

Percent yield = 52.6 %

3 0
3 years ago
Consider an atom having four distinct energy levels. If an electron is able to make transitions between any two levels, how many
Kryger [21]

Energy levels are the electron shells where electrons are found at a fixed distance from the nucleus of the atom. The atom could emit 6 different wavelengths.

<h3>What is wavelength?</h3>

A wavelength is a distance between the adjacent crests in wave signals propagated in a system. Wavelength (\rm \lambda ) is in inverse relation to the frequency of the wave.

When an electron jumps from energy level 1 to 2, 1 to 3, and 1 to 4 one wavelength each is present. Hence, making the total wavelength to be 3, in transition from the first energy level.

Similarly, from energy levels, 2 to 3 and 2 to 4, a total of 2 wavelengths, and from energy levels 3 to 4 one wavelength is produced.

So the total different wavelengths of the radiation that can be emitted will be 3 + 2 + 1 = 6.

Therefore, 6 different wavelengths of radiation will be emitted by the atom.

Learn more about wavelengths here:

brainly.com/question/21419520

#SPJ1

7 0
2 years ago
Find the reagent to sythesize 1- phenyl-1-propanol
vova2212 [387]

Answer:

aqueous acid is used as a reagent.  

Explanation:

Addition of Grignard reagent in aldehyde and followed by the acidification give rise to the primary or secondary alcohol. when the formaldehyde is used than the primary alcohol is formed otherwise secondary alcohol is formed.

in this reaction we also use the aqueous acid for the acidification as a reagent. We add aqueous acid when ethanol is present. This is because ethanol is get converted in the presence of aqueous acid into the chloroethane.  

4 0
3 years ago
Give an example of how environmental science might involve geology and chemistry.
Sever21 [200]
One of the examples is radiation and chemistry of water. Environmental science requires the capacity to integrate data from the greater part of the significant fields of science, and in addition from arithmetic. 
Geology is vital on the grounds that huge scale arrives forms make geology. The presence of mountains and valleys influences how much daylight and precipitation achieve the ground, how breezy an area is, the manner by which precipitation keeps running off, and numerous different variables that figure out what plants and creatures will have the capacity to occupy a district.
8 0
3 years ago
A combination reaction occures when one element replaces another element in a compound during a chemical reaction
PIT_PIT [208]
That is false.... I hope this is true or false
5 0
3 years ago
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