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Question 13 / 40
When electrons move from a high energy level to a low energy level, which of the following statements are correct?
spectral lines are emitted
mass is converted to energy
the photoelectric effect occurs
quarks combine to create subatomic particle​

Answer:

Light

Explanation:

Light is a good example of invisible particles. We cannot see light particles aka photon. We only know the light is present by the objects we see. Because we can only see objects when light reflects from them on our eyes.

[I could only think of one example if I can remember one more I'll edit it down]

Explanation:

Reaction of zinc metal in copper sulfate solution.

[tex]\begin{array}{ll}\text { Oxidation : } & \mathrm{Zn}(s) \rightarrow \mathrm{Zn}^{2+}(a q)+2 e^{-}\\\text {Reduction : } & \mathrm{Cu}^{2+}(a q)+2 e^{-} \rightarrow \mathrm{Cu}(s) \\\hline \text { Full Reaction : } & \mathrm{Zn}(s)+\mathrm{Cu}^{2+}(a q) \rightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cu}(s)\end{array}[/tex]

Zinc is listed above copper on the activity series, this means that zinc is more easily oxidized than copper. That is why copper(II) ions can act as an oxidizing agent when put into contact with zinc metal. Ions of any metal that is below zinc, such as lead or silver, would oxidize the zinc in a similar reaction.

The percent  by volume of a solution : 19.23%

Given

50 ml of ethanol

210  ml of water

Required

The percent  by volume of a solution

Solution

Percent Volume (% v/v) : volume (ml) of solute/100 ml of solution ⇒ ratio of the volume of the solute to total volume of the solution

[tex]\tt \%solute(v/v)=\dfrac{solute~volume}{solution~volume}\times 100\%[/tex]

solute= Ethanol

solvent=water

Solution = solute+solvent

Total volume of the solution :

[tex]\tt =volume~of~Ethanol+solume~of~water\\\\=50~ml+210~ml\\\\=260~ml[/tex]

Percent by volume :

[tex]\tt \%volume=\dfrac{50}{260}\times 100\%\\\\\%volume=19.23\%[/tex]

Answer:

Probably B?

Explanation:

I don't have one...

Hope it helps I guess..

Answer: i think is B

Explanation: HATE ME IF IM WRONG

Answer:

F

Explanation:

Answer:

Moles of tin = 0.37 mol

Explanation:

Given data:

Mass of tin oxide = 50 g

Moles of tin = ?

Solution:

Number of moles of SnO:

Number of moles = mass/molar mass

Number of moles = 50 g/ 134.71 g/mol

Number of moles = 0.37 mol

We can see there is only one mole of Sn is present in one mole of tin oxide.

Thus in 0.37 mol  of tin oxide,

0.37 mol × 1 = 0.37 mol of tin

Answer:

the number of moles of atom is 0.91584

Answer:

100

Explanation:

nsvcscjkvschssvds

Answer/Explanation:

#1 - A pure substance is either an element or a compound, making it different from a mixture. A sample of matter that has specific chemical and physical properties is the only one that fits here.

#2 - A pure substance is either an element or a compound, making it different from a mixture. Water is a compound, and thus this would be true.

#3 - An atom is the smallest unit of an element that keeps the properties of that element. Just refer to its definition.

#4 - A molecule is two or more atoms held together by chemical bonds . Again, just refer to its definition.

#5 - A chemical bond is the attractive force that holds atoms together . Jus refer to its definition.

#6 - Molecules are most definitely not all the same size, especially given the huge number of them. This would be false.

#7 - A compound is a pure substance made up of two or more different types of atoms joined by chemical bonds . Just refer to its definition.

#8 - Compounds always form in a fixed ratio, so this would be false.

#9 - If by directly, the problem means with the naked eye, this would be true.

#10 - False. It's reversed.

#11 - A crystal is a substance in which the particles are arranged in an orderly, geometric, and repeating pattern . Just refer to its definition.

#12 -True; to be more specific, they are covalent network solids.

answer is attached in the image below

Answer:

Hydrochloric Acid

Explanation:

Answer:

Since 1 L equals to 1000 microlitres, and 1 microlitre equals to 1 gram, there are 56 * 1000 = 56000 grams of chlorine gas in 56 L of chlorine gas.

Explanation:

Hope this helped!

Answer:

chloroplasts, cell walls, or intracellular vacuoles

Explanation:

You didn't list the following, but I'm guessing it is chloroplasts, cell walls, or intracellular vacuoles

Answer:

Explaining dark matter and black holes

Here are six big questions about our universe that current physics can’t answer:

What is dark energy, the mysterious energy that appears to be accelerating the expansion of the universe?

What is dark matter, the invisible substance we can only detect by its gravitational effect on stars and galaxies?

What caused inflation, the blindingly fast expansion of the universe immediately after the Big Bang?

For that matter, what caused the Big Bang?

Are there many possible Big Bangs or universes?

Is there a telltale characteristic associated with the death of a universe?

Despite the efforts of some of the world’s brightest brains, the Standard Model of particle physics – our current best theory of how the universe works at a fundamental level – has no solution to these stumpers.

A compelling new theory claims to solve all six in a single sweep. The answer, according to a paper published in European Physical Journal C by Herb Fried from Brown University and Yves Gabellini from INLN-Université de Nice, may be a kind of particle called a tachyon.

Tachyons are hypothetical particles that travel faster than light. According to Einstein’s special theory of relativity – and according to experiment so far – in our ‘real’ world, particles can never travel faster than light. Which is just as well: if they did, our ideas about cause and effect would be thrown out the window, because it would be possible to see an effect manifest before its cause.

Alt

Explanation:

Due to travelling faster than light, dark matter has a higher than usual mass in relation to its resting mass, thus accounting for the large 'missing' mass around galaxies. ... Dark matter is therefore non-baryonic, travelling faster than light and has a mass half that of a photon...

bts army forever.....vzgGgzs0

.......JK

.....justin bieber

Answer:

Normality of KOH = 0.1062 N

Note: The given question is not clearly stated. A related question below is answered and explained;

What is the NORMALITY of a solution of KOH if 45.18 mL are required to neutralize 0.3g of pure oxalic acid H2C2O4 . 2H2O?

Explanation:

Equation of the reaction: 2KOH + H₂C₂O₄.2H₂O --> K₂C₂O₄ + 4H₂O

molar mass 0f KOH = 56 g/mol; molar mass of H₂C₂O₄.2H₂O = 126 g/mol

Number of moles of in 0.3 g of H₂C₂O₄.2H₂O = mass/molar mass

number of moles = 0.3 g / 126 g/mol = 0.0024 moles

From the equation of reaction, 2 moles of KOH are required to neutralize 1 mole of H₂C₂O₄.2H₂O

Number of moles of KOH required to neutralize 0.0024 moles of H₂C₂O₄.2H₂O = 2 * 0.0024 = 0.0048 moles

Molar concentration of 45.18 mL solution of KOH containing 0.0048 moles of  KOH = number of moles/volume (L)

molarity of KOH solution = (0.0048/45.18 mL) * (1000 mL/1 L) = 0.1062 mol/L

Normality = n * molarity

where is the number of moles of OH⁻ ions produces from  mole of KOH = 1

Normality of KOH = 1 * 0.1062

Normality of KOH = 0.1062 N

Answer:

See explanation

Explanation:

The equation of the reaction is;

CH3COOCH3 + H2O -------> CH3COOH + CH3OH

Now recall that the rate of reaction refers to the rate of disappearance of reactants or the rate of appearance of products. We indicate that reactants disappear by a negative sign placed in front of the concentration term of reactants.

Rate = k -d[CH3COOCH3]/dt

Rate = k d[CH3COOH]/dt

Rate = k d[CH3OH]/dt

Note; i did not write the rate in terms of water because it is a solvent that is present in large excess. Its concentration does not change with time.

Answer:

Q = 9460 Kj

Explanation:

Given data:

Mass of copper = 2kg

Latent heat of vaporization = 4730 Kj/Kg

Energy required to vaporize 2kg copper = ?

Solution:

Equation

Q= mLvap

It is given that heat required to vaporize the one kilogram copper is 4730 Kj thus, for 2 kg

by putting values,

Q= 2kg ×  4730 Kj/Kg

Q = 9460 Kj

Ionic and covalent bonds can occur in substances that have a repeating lattice structure.

Ionic bonds are formed when an atom donates electron (s) to another atom. Covalent bonds, on the other hand, are formed when two atoms share electrons to complete their octet states.

Ionic compounds are formed from a combination of metal and non-metal atoms. They usually have crystalline lattice structures with high melting points.

Covalent compounds are formed between non-metal atoms. They can also have lattice structures but generally have lower melting points because the forces holding the molecules together are weaker.

More on ionic and covalent bonds can be found here: https://brainly.com/question/10777799

#SPJ1

Answer:

Occurs in substances that have a repeating lattice structure

Explanation:

Answer:

is the getting out of a gas in a water solution or it the property of forming bubbles

The chemical formula of sodium hydroxide is NaOH, and its molar mass is 40.01 g/mol. It is the alkali salt of sodium, and its structure is shown below:

It is an ionic compound consisting of sodium cation (Na+) and hydroxide (OH-) anion.

Answer:

6.3 moles of water = 6.3*18=113.4 grams per mole

Explanation:

B. Kids should go to school for 12 years.

Scientific statements are those statements that must be falsifiable which means that able to be proven false while on the other hand, tautology is a statement that is true. The sun revolves around the earth” is an example of scientific statement because this statement can be falsifiable in the light of evidences and researches. Hypothesis is a statement that may be true or false. We can verify it by doing experiments.

So we can conclude that option B is the sentence that represents a scientific statement.

Learn more about scientific here: https://brainly.com/question/17216882

#SPJ1

Answer:

Chemical energy _ thermal energy

Answer:

sodium

Explanation:

nitrogem, phosphorous and potassium are very important to plant growth, but sodium isnt necessary.

Answer:

the answer is sodium hope this helps

Answer:

It contain double Bond.

Explanation:

To determine weather the bond is double or triple simply check the electron involved in mutual sharing of an electron if 2 electron takes parts it said to be double or if 3 it said to be triple.

Answer:

D

Commutator is the answer

Explanation:

The commutator systematically converts the current direction between the rotor and the outer circuit. As the shaft revolves, the commutator converts the course of current in a winding. For a separate armature winding, when a cylinder has reached one-half perfect turn, the winding is now attached so that current passes through it in the reverse of the original direction.

Answer:

D. Commutator

Explanation:

I just took the quiz. credit to the person above me.

Answer: x108(5.03x−42.6)

Explanation: Factor 5.03x109−42.6x108

5.03x109−42.6x108

=x108(5.03x−42.6)