Ai là nhà Hoá học nổi tiếng nhất ở Việt Nam? Ông đã có những đóng góp gì cho xã hội?

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Answer 1

Answer:

Are you spraking Vietnamese?


Related Questions

1. Atoms are
a. The smallest building blocks of matter
b. Subatomic particles
c. Charged particles
d. Made up of leptons.

Answers

Answer:

a.the smallest building blocks of matter

Explanation:

because atoms are the smallest building blocks of matter.

The answer is A the smallest building blocks of matter.

Explain the purpose of the magnet in a mass
spectrometer.

Answers

Answer:

The magnetic sector mass spectrometers use a bending magnet: When the ions or atoms enter the magnet, they are forced to bend, and the light ions bend sharper than the heavy ions, as a result of which they're separated into a spectrum, like a rainbow.

Explanation:

Hope This Helps!

please explain bonding of CCl 4

Answers

Answer:

CCl4 is a covalent bonded nonpolar molecule.

Explanation:

Although there is an electronegativity (small) difference between C and Cl, its structure with 4 chlorine atoms allows the polarity to be "canceled out." I have attached a picture of the molecule below where you can clearly see the dipole movement on either side gets canceled hence making it have no net dipole movement. Additionally, CCl4 has a total number of valence electrons to be 32. 7 for one chlorine atom and 4 for a carbon one. The octets are satisfied as well. It's covalent because carbon and chlorine are nonmetals.

identify each pair of compounds as constitutional isomers, stereoisomers, identical molecules, or other.

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I don’t know this answer

The graph represents the heating of water in a pot. At 150 seconds, the water has just reached a boil. If the heat is left on, what will happen to the temperature and volume of water in the pot? (All temperatures in °C.)

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Temperature will raise and water will evaporate

How is the brain related to the nervous system?
All nerve cells are connected to the brain.
The brain is in charge of reproducing more nerve cells.
The nervous system controls the brain.
The brain is in charge of all nerve cells in the body.

Answers

Answer:

it is a ty hope this helps

Explanation:

El porcentaje en masa de una solución de azúcar en agua es de 3.8%, si se tienen 6.3 Kg de solución ¿Cuántos gramos de azúcar hay​?

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La cantidad de azúcar en la solución es 239.4 gramos. En este caso, el azúcar es el soluto, y el agua el solvente.

El azúcar es el soluto el cual se encuentra disuelto en una solución acuosa que posee una masa de 6.3 kilogramos.

Un kilogramo equivale a 1,000 gramos. Es decir, 1 Kilogramo (kg) = 1,000 gramos (gr).

Entonces, la cantidad de azúcar puede ser calculada utilizando la regla de tres simple >>

6,300 gr ________ 100 %

X ______________ 3.8 %

X = (3.8 x 6,300)/ 100 = 239.4 gr

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If you change the 2 in front of 2O2 to a 3, what will be the change in the results on the right side of the equation? (1 point)

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Answer:

There is an extra O2 molecule left over

Explanation:

Cho 40 gam tác dụng (Al, Cu) vừa đủ với 600 gam dd HCl 14,6%. Tính% khối lượng Al, Cu

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попробуйте запросить поисковую систему и скопируйте и вставьте вопрос

Help with #3 please. I’ll mark brainly

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The control Group

The control group is the group of mold spores that were not exposed to ultraviolet light, left in the darkness and as such were not altered. Control groups are not altered and serve as some form of measurement of the experimental group. The experimental group is the mold spores group exposed to ultraviolet light and observed to note the difference between it and the control group

Answer:

sa gutan ko na nga para mabrainliest na sya

The allotropic form of a non – metal is a good conductor of electricity. Name the nonmetal.

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Answer:

carbon with graphite as the allotrope

Ned help with this question​

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100/0.25 = 400 cm^3

2. You are given a mixture of sand, salt, metal filings and small stones. What would you do to separate all four items?

I’ll give brainliest, thanks, 5 stars to the best answer that has been explained properly

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Answer: Well, I'd personally go with the tedious route and pick them all out by hand, but I know what doesn't really help. Just a suggestion though, sorry.

Explanation: Don't listen to my advice if you want any free time.

Answer:

Start by using a magnet to separate out the metal fillings.

Then put the mixture through a sieve to separate out the stones.

Then mix it into water and drain out the sand.

Finally, boil the water off to get the salt back.

Explanation:

The metal fillings should be magnetic, and so a magnet will attract only the metal and allow you to remove it.

Putting the mixture through a sieve will basically sift it, since the sand and salt will fall through the holes but the rocks will be too big.

Mixing the mixture into water will dissolve the salt but not the sand, allowing you to pour off the water and be left with sand.

Boiling the water will cause the H2O to become a vapor, while leaving the salt behind.

1.Give the correct order of apparatus (Evaporating dish, Filter funnel, Test tube, Dropper, Spatula) to show the correct arrangement that can be used to prepare and investigate the nature of pH of a sample of onion solution.

2.Name an apparatus and a chemical used in this experiment.

Answers

Answer:

2 answer

A List of Chemistry Laboratory Apparatus

Safety goggles and safety equipment.

Beakers.

Erlenmeyer flasks, AKA conical flasks.

Florence flasks, AKA boiling flasks.

Test tubes, tongs, and racks.

Watch glasses.

PLEASE I NEED HELP
A student uses the periodic table to map out the trend in increasing atomic radii. During peer feedback, a student mentions that her trend is incorrect. Which model and explanation should the student use to help the student understand?

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the third one, or the first one in the second picture.

i read up on this like a year ago so i think i’m right but i can’t be too sure. i hope this helps you, good luck!

Atomic radius decreases across the period and increases down the group.

The atomic radii is a periodic trend that decreases across the period and increases down the group. Periodic trends are properties of elements that increase or decrease down the group or across the period.

As more positive charges (protons) are added to the nucleus as we move across the period, the attractive force between electrons and protons increases. As such atomic radii decreases across the period.

Down the group, addition of more shells leads to increased electronic repulsion which causes that atomic radii of elements to increases as we move down the group.

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How is half life used in today’s society?

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Answer:

to judge outcomes

Explanation:

draw molecular structure of Sodium oxide​

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Answer:

I think it is right.

please make me brainliest

Answer:

I hope it will help you so . Have a great day.

A student determined that shaking a container of sand caused the temperature of the sand to rise. The student then performed a new experiment to see if shaking a container of pebbles would cause the temperature of the pebbles to rise.

Explain why the shaking caused the temperature of the sand to rise.

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Example: When you rub your hands together, the action of scraping the surface of your skin back and forth against each other causes the molecules in your skin to move a little faster. The faster that molecules move, the higher the temperature. So the friction of rubbing your hands together makes them feel warmer.
So when you shake the sand the molecules move faster make the temperature warmer.

The shaking caused the temperature of the sand to rise because hey should notice an increase in sand temperature as the kinetic energy increases. This is due to the fact that the kinetic energy from their shaking is being converted to thermal energy in the sand.

What causes the temperature of the sand to change?

The sand is a poor heat conductor because when the Sun warms it, the heat is not distributed evenly, making the surface hot. Also, because sand has a lower specific heat than water, when both are exposed to the same amount of light, the sand at the surface will experience a greater change in temperature.

When you rub your hands together, the action of scraping the surface of your skin back and forth against each other causes the molecules in your skin to move a little faster.

The faster that molecules move, the higher the temperature. So the friction of rubbing your hands together makes them feel warmer.

Thus, when you shake the sand the molecules move faster to make the temperature warmer.

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what is the role of plastocyanin in the z-scheme model?

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Answer:

It shuttles electrons between the cytochrome complex and photosystem I.

Explanation:

Given that the density of Al is 2.702 g/mL, determine the volume of a 6.80 g aluminum cube.

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Answer:

2.52 mL

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

From the question we have

[tex]volume = \frac{6.8}{2.702} \\ = 2.516654[/tex]

We have the final answer as

2.52 mL

Hope this helps you

If the density of copper is 8.96 g/cm3, and the mass of a sample is 5.00 g, what is the volume of the copper?

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Answer:

The density is the same, so

 

(6000 g)/V = 8.96 g/cm3

 

V = 6000/8.96 cm3 = 669.64 cm3

Explanation:

molecular structure of sodium oxide​

Answers

Answer:

madami DA pat hung texture

I HOPE IT WILL HELP YOU.

Thank you.

TEDDYLOVER.

What orbital does the quantum numbers n=4 l=2 ml=2 describe

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Answer:

Orbital designation

for Principle Quantum number n=4, this is the shell number & corresponds to N shell, (shells are designated K,L,M,N)

for Angular Momentum number l=2, this is the orbital level corresponding to d, given that l can be any integer 0-(n-1), for( 0,1,2,3 )corresponds to (s, p, d, f)

The orbital designation is 4d

for Magnetic Quantum number ml, the suborbitals correspond to -l through l, (-2,-1,0, 1,2)

for ml=-1 the suborbital -1 in the 4d sub shell with electron spin state ms=-1/2

What is the volume of 1.0 mole of gas at a pressure of 3.12 ATM and a temperature of 270K

Answers

Answer: 7.13 L

Explanation:

What is the volume of 1.0 mole of gas at a pressure of 3.12 ATM and a temperature of 270K

AT STP OF 1 ATM OF PRESSURE AND 273K ONE MOLE OF GAS OCCUPIES 22.4 L

WE HAVE MORE THAN TRIPPLED THE PRESSURE AND SLIGHTLY LOWERED THE TEMP

THE NEW VOLUME WILL BE 22.4 x (1/3.12) x 270/273 =7.13 L

True or False:
11. The water cycle has no start or end.
12. When water turns into a gas this is called evaporation.
13. The amount of water on the Earth grows by 0% each year.
14. Evaporation can only occur in salt water.
15. More evaporation occurs during the day.
A. True
A. True
A. True
A. True
A. True
B. False
B. False
B. False
B. False
B. False

Answers

Answer:

11) True

12) True

13) False

14)False

15) True

Explanation:

Hope this helps!

Have a nice day! :D

Can someone tell me what this is ?

Answers

Answer:

ruler

Explanation:

that's what we call a ruler

Answer:

2 centemeters and 8 milimeters

Explanation:

A coefficient serves which purpose in a chemical equation?

Answers

The coefficient indicates the number of molecules in what seems like a mathematical theorem or formula. A more comprehensive explanation follows.

Coefficients seem to be quantities, integers as well as words that are added in front of the same biochemical representation or expression just to counterbalance chemical formulas.The function of coefficients together in balanced chemical would be to represent the proportion wherein the starting materials mix during a reaction.

Thus above response is right.

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True or false: The nucleus occupies most of the space of an atom.

Answers

Answer:

True, typically, the nucleus contains more than 99.9% of the mass of an atom.

Explanation:

True, the nucleus is the biggest part of an atom.

PLEASE HELP!!!
A student makes a graph of ionization energy using the periodic table.
Which claim is most supported by the trends in the periodic table represented in this graph?

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Explanation:

the option 2 is correct

metals tend to have lower ionizatiin energy than non metals

Which is the best hypothesis to use for this investigation

Answers

Answer:

Wdym?? there is no other hypotheses stated

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