X-ray crystallography is used to see the structure of molecules. Scientists have used this technique to find the structure of cholesterol, an important biological molecule.

Knowledge of the structure of cholesterol is helpful because it may affect
A. how cholesterol works in the body.
B. the amount of cholesterol that is considered healthy.
C. previous ideas about which foods contain cholesterol.
D. previous explanations of how cholesterol works in the body.

Answers

Answer 1

Answer:

A. how cholesterol works in the body.

Explanation:

If we know the precise structure of a molecule (by X-ray crystallography), we can understand more about how it interacts with cells, proteins, and other molecules. It can also tell us what reactions it might take part in.

Therefore, we can learn more about how it works in the body and what activities it takes part in in the cells of the body.

Answer 2

Answer:

A

Explanation:

nuityyy


Related Questions

The density of two liquids, A and B, are 1000. kg/m3 and 600. kg/m3, respectively. The two liquids are mixed in a certain proportion and the density of the resulting liquid is 850 kg/m3. How much of liquid B (in grams) does 1.0 kg of the mixture contain? Assume the volume of the two liquids is additive when mixed.

Answers

Answer:

Mass of liquid B = 271.2 gram

Explanation:

Given:

Density of liquid A = 1000 kg/m³

Density of liquid B = 600 kg/m³

Density of mixture = 850 kg/m³

Mass of mixture = 1 kg

Assume:

Volume of liquid A = Va

Volume of liquid B = Vb

So,

Volume of mixture = Va + Vb

Mass of liquid A = 1000(Va)

Mass of liquid B = 600(Vb)

Mass of mixture = Mass of liquid A + Mass of liquid B

1 = 1000(Va) + 600(Vb)

Volume of mixture = 1 / 850

So,

(1/850) = Va + Vb

Vb = (1/850) - Va

1 = 1000(Va) + 600[(1/850) - Va]

Va = 7.25 × 10⁻⁴

Vb = (1/850) - Va

Vb = (1/850) - [7.25 × 10⁻⁴]

Vb = 4.25 × 10⁻⁴

Mass of liquid B = 600(Vb)

Mass of liquid B = 600(4.25 × 10⁻⁴)

Mass of liquid B = 271.2 gram

The mass of liquid B in the 1 Kg mixture is 300 g

Let the volume of liquid A be Va

Let the volume of liquid B be Vb

From the question given above, the following data were obtained:

Density of liquid A = 1000 kg/m³

Density of liquid B = 600 kg/m³

Density of mixture = 850 kg/m³

Mass of mixture = 1 kg

Mass of Liquid B (in grams) =?

Next, we shall determine the mass of liquid A and B

For Liquid A:

Density of liquid A = 1000 kg/m³

Volume of liquid A = Va

Mass of Liquid A =?

Mass = Density × Volume

Mass of Liquid A = 1000 × Va

Mass of liquid A = 1000(Va)

For Liquid B:

Density of liquid B = 600 kg/m³

Volume of liquid B= Va

Mass of Liquid B =?

Mass = Density × Volume

Mass of Liquid B = 600 × Va

Mass of liquid B = 600(Vb)

Next, we shall determine the volume of the mixture.

Density of mixture = 850 kg/m³

Mass of mixture = 1 kg

Volume of mixture =?

Volume = mass /density

Volume of mixture = 1 / 850

Volume of mixture = 0.0012 m³

Next, we shall determine the volume of liquid A

Mass of mixture = 1 Kg

Mass of mixture = Mass of liquid A + Mass of liquid B

1 = 1000(Va) + 600(Vb) ....... (1)

Volume of mixture = Va + Vb

Volume of mixture = 0.0012 m³

Thus,

0.0012 = Va + Vb

Vb = 0.0012 – Va ........ (2)

Substitute Vb in equation 2 into equation (1)

1 = 1000(Va) + 600[0.0012 – Va]

1 = 1000Va + 0.72 – 600Va

Collect like terms

1 – 0.72 = 1000Va – 600Va

0.28 = 400Va

Divide both side by 400

Va = 0.28 / 400

Va = 0.0007 m³

Next, we shall determine the volume of the liquid B

Volume of mixture = 0.0012 m³

Volume of liquid A (Va) = 0.0007 m³

Volume of liquid B (Vb) =?

Vb = 0.0012 – Va

Vb = 0.0012 – 0.0007

Vb = 0.0005 m³

Finally, we shall determine the mass of liquid B

Volume of liquid B (Vb) = 0.0005 m³

Mass of liquid B = 600(Vb)

Mass of liquid B = 600(0.0005)

Mass of liquid B = 0.3 Kg

Multiply by 1000 to express in grams

Mass of liquid B = 0.3 × 1000

Mass of liquid B = 300 g

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7. A cyclist starting from rest accelerates at a rate of 6 m/s until she reaches 30 m/s. How long
does it take her to accelerate?

Answers

Answer:

Explanation:

The given values are:

a= 6m/s²

u= 0 m/s

v = 30 m/s

t= ?

The formula is :

[tex]a=\frac{v-u}{t}[/tex]

thus,

[tex]t=\frac{v-u}{a}\\t=\frac{30-0}{6}\\t= 5 seconds[/tex]

What ionic substance is being used to illustrate the concept of lattice energy in Model 1?

Answers

Answer:

magnesium oxide

Explanation:

hope this helps

the answer is magnesium oxide

Sort each of the following elements by effective nuclear charge, Zeff, from smallest to largest:
Sn, Rb, Sb, In, and Sr​

Answers

Answer:

Rb = +1 , Sr = +2, In= +3,  Sn = +4, Sb= +5

Explanation:

Formula:

Zeff = Z - S

Z = atomic number

S = number of core shell or inner shell electrons

For Sn:

Electronic configuration:

Sn₅₀ = [Kr] 4d¹⁰ 5s² 5p²

Zeff = Z - S

Zeff = 50 - 46

Zeff = +4

For Rb:

Electronic configuration:

Rb₃₇ = [Kr] 5s¹

Zeff = Z - S

Zeff = 37 - 36

Zeff = +1

For Sb:

Electronic configuration:

Sb₅₁ = [Kr] 4d¹⁰ 5s² 5p³

Zeff = Z - S

Zeff = 51 - 46

Zeff = +5

For In:

Electronic configuration:

In₄₉ = [Kr] 4d¹⁰ 5s² 5p¹

Zeff = Z - S

Zeff = 49 - 46

Zeff = +3

For Sr:

Electronic configuration:

Sr₃₈= [Kr]  5s²

Zeff = Z - S

Zeff = 38 - 36

Zeff = +2

Danielle is asked to determine the density and the identity of a metal. She determines the mass of the metal to be 102.06g and then determines the volume of the sample using water displacement. Find the density. Round the answer to the nearest whole number?

Answers

Answer:

11 g/mL

Explanation:

From the question given above, the following data were obtained:

Mass of metal = 102.06 g

Volume of water = 38 mL

Volume of water + metal = 47 mL

Density of metal =.?

Next, we shall determine the volume of the metal. This can be obtained as shown below:

Volume of water = 38 mL

Volume of water + metal = 47 mL

Volume of metal =..?

Volume of metal = (Volume of water + metal) – (Volume of water)

Volume of metal = 47 – 38

Volume of metal = 9 mL

Finally, we shall determine the density of the metal as follow:

Mass of metal = 102.06 g

Volume of metal = 9 mL

Density of metal =.?

Density = mass /volume

Density of metal = 102.06 / 9

Density of metal = 11.34 ≈ 11 g/mL

Therefore, the density of the metal is 11 g/mL

N2(g) + 2H(g) -> N2 H4(g) What are the volumes of N2 gas and H2 gas required to form 28.5 grams of N2 H4 at 30'C and 1.50 atm?

Answers

Answer:

Volume of N₂ = 14.76 L

Volume of H₂ = 29.52 L

Explanation:

Given data:

Mass of N₂H₄ formed = 28.5 g

Pressure = 1.50 atm

Temperature = 30°C (30+273 = 303 k)

Volume of N₂ and H₂ needed = ?

Solution:

Chemical equation:

N₂ + 2H₂  →  N₂H₄

Number of moles of N₂H₄ formed = mass/ molar mass

Number of moles of N₂H₄ formed = 28.5 g/ 32 g/mol

Number of moles of N₂H₄ formed = 0.89 mol

Now we will compare the moles of N₂H₄ with N₂ and H₂ form balance chemical equation.

                N₂H₄                :                 N₂

                   1                     :                   1

                  0.89               :               0.89

                N₂H₄                :                 H₂

                   1                    :                  2

                 0.89               :                2×0.89 = 1.78 mol

Volume of H₂:

PV = nRT

1.50 atm × V = 1.78 mol × 0.0821 atm.L/mol.K × 303 K

V = 44.28atm.L /1.50 atm

V = 29.52 L

Volume of N₂:

PV = nRT

1.50 atm × V = 0.89 mol × 0.0821 atm.L/mol.K × 303 K

V = 22.14 atm.L /1.50 atm

V = 14.76 L

Question 14
4 pts
Using the formula Na + Cl2 --> Naci, if 2.98 moles of sodium are combined with
excess" chlorine, how many moles of sodium chloride will be made? Note that in
this question, excess means extra or as much as you need.

Answers

Answer:

2.98 moles of NaCl are produced.

Explanation:

Given data:

Moles of sodium = 2.98 mol

Amount of chlorine = excess

Moles of NaCl produced = ?

Solution:

Chemical equation:

2Na + Cl₂    →     2NaCl

Now we will compare the moles of sodium chloride with only sodium because sodium is limiting reactant and chlorine is in excess thus sodium limit the yield of product.

                    Na        :        NaCl

                    2          :            2

                 2.98        :          2.98

2.98 moles of NaCl are produced.

Ag3PO4 what is the compound with this formula

Answers

Answer:

silver (III) phosphate

Explanation:

Which answer below correctly identifies the type of change and the explination for the boiling of water

Answers

Answer:

Physical change because even though gas formation was observed, the water was undergoing a state change, which means that its original properties are preserved.

Explanation:

Water boiling results in the physical state changing from solid to gaseous water. This moment can be called boiling or vaporizing, which is the change from liquid to gaseous state by heating water. Thus, the "Boiling Point" (PE) of a substance is the temperature at which that substance changes from liquid to gaseous state and, in the case of water, is 100 ° C. When the water reaches this temperature its physical change occurs because, despite the formation of gas, the water was undergoing a state change, which means that its original properties are preserved.

Which characteristics of stars is affected by a star's temperature?

Answers

Answer:

Characteristics of stars is affected by a star's temperature is Color.

Explanation:

As the color of stars is completely dependent upon its own surface temperature. If the stars are cooler, then it turns red in color. If the stars are hotter, then it turns blue in color.

Mintu wants to increase the heat transfer between a metal iron and another piece of metal he wants to shape. He decides to increase the time the two metals are in contact, use a larger metal iron, and use a new metal material with a higher specific heat.

Where is Mintu's error?

Answers

Mitu should have chosen a material with a lower specific heat .

Answer:

Mintu should chosen a material with a lower specific heat

Explanation:

I got the answer right on the test trust me it is correct

The effectiveness of nitrogen fertilizers depends on both their ability to deliver nitrogen to plants and the amount of nitrogen they can deliver. Four common nitrogen-containing fertilizers are ammonia, ammonium nitrate, ammonium sulfate, and urea [(NH2)NH2) 2CO2CO)]. Rank these fertilizers in terms of the mass percentage nitrogen they contain. Rank fertilizers from largest to smallest mass percentage nitrogen they contain. To rank fertilizers as equivalent, overlap them.

Answers

Answer:

Ammonia > Urea > Ammonium nitrate > Ammonium sulphate

Explanation:

Percentage by mass of nitrogen in NH3:

Molar mass of NH3= 17 g/mol

Hence % by mass = 14/17 × 100 = 82.35%

% by mass of NH4NO3

Molar mass of NH4NO3 = 80.043 g/mol

Hence; 28/80.043 × 100 = 34.98%

% by mass of (NH4)2SO4;

Molar mass of (NH4)2SO4= 132.14 g/mol

Hence; 28/132.14 × 100 = 21.19%

% by mass of CH4N2O

Molar mass of urea = 60.0553 g/mol

Hence 28/60.0553 × 100 = 46.62%

What conclusion is best supported by the decay chain?
A) Each alpha decay results in an isotope that is slightly more stable than the original isotope.
B) Each beta decay results in an isotope that is slightly more stable than the original isotope.
C) The atomic number increase caused by two beta decays is the same as the decrease caused by one alpha decay.
D) The mass number increase caused by two beta decays is the same as the decrease caused by one alpha decay.

Answers

Answer:

C. The atomic number increase caused by two beta decays is the same as the decrease caused by one alpha decay.

Answer:

c. The atomic number increase caused by two beta decays is the same as the decrease caused by one alpha decay.

Explanation:

got it correct on quiz

How many elements are in a isotope?

Answers

Answer:i believe 9-?

Explanation:

boron-10

boron-11

carbon-12

carbon-13

oxygen-16

oxygen-17

oxygen-18

chlorine-35

chlorine-37

What will an object moving at a constant velocity do?
come to a stop, unless it is pushed by another force
A.increase in speed
B.maintain a constant velocity until acted on by another force
C.come to a stop on its own

Answers

Answer:B

Explanation: an object in motion will stay in motion until acted on by another force and an object in rest will stay in test until acted on by another force

4- Calculate the mol fraction of ethanol and water in
a sample of rectified spirit which contains 95% of
ethanol by mass.​

Answers

Answer:

math si hard

Explanation:

The mole fration of ethanol and water in a sample of rectified spirit which contains 95% of ethanol by mass is 0.8 and 0.11.

How do we calculate mole fraction?

Mole fraction of any substance will be calculated by dividing the moles of that substance from the total moles of the solution.

Moles (n) will be calculated as:

n = W/M, where

W = given mass

M = molar mass

Given that 95% of ethanol by mass is present in the sample, so 95g of ethanol is present in 100g of solution.

Mass of solvent (water) = 100 - 95 = 5g

Moles of water = 5g / 18g/mol = 0.27mol

Moles of ethanol = 95g / 46g/mol = 2.06mol

Mole fraction of water  = 0.27 / (0.27+2.06) = 0.11

Mole fraction of ethanol = 2.06 / (0.27+2.06) = 0.8

Hence required mole fraction of water & ethanol is 00.11 and 0.8 respectively.

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30 points!!! please help chem question

Answers

Answer: below -45

Explanation:

One of the physical properties of bases is that they ____.
Question 17 options:

taste sour

feel slippery

crumble

corrode metal

Answers

Answer:

feel slippery

Explanation:they physical properties are due to its slippery nature when touched

are there more metals or nonmetals on the periodic table?

Answers

Answer:yes

Explanation:

I think so

There are more metals than nonmetals on the periodic table. The majority of elements on the periodic table are metals, which are found on the left and middle sections of the periodic table.

Metals typically have properties such as high electrical and thermal conductivity, luster, malleability, and ductility.

Nonmetals, on the other hand, are found on the right-hand side of the periodic table, along with the noble gases. Nonmetals generally have properties opposite to those of metals, such as poor electrical and thermal conductivity and a lack of metallic luster. There are fewer nonmetals compared to metals on the periodic table.

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Define molecular mass. Calculate the molecular mass of calcium carbonate
and nitric acid.

Answers

Answer:

HNO₃ =63.0147 g/mol

CaCO₃ = 100.088 g/mol

Explanation:

Molecular mass:

It is the sum of all the atomic masses of the atoms of elements present in a molecule.

For example:

The formula of CaCO₃:

Calcium carbonate consist of one atom of calcium, one atom of carbon and three atoms of oxygen. Thus, its molecular mass would be,

CaCO₃ = 40.078 × 1 + 12.01×1 + 16.00×3

CaCO₃ = 40.078 + 12.01+ 48

CaCO₃ = 100.088 g/mol

The formula of HNO₃:

Nitric acid consist of one atom of hydrogen, one atom of nitrogen and three atoms of oxygen. Thus, its molecular mass would be,

HNO₃ =1.008 × 1 + 14.0067 ×1 + 16.00×3

HNO₃ = 1.008 +14.0067 + 48

HNO₃ =63.0147 g/mol

Calculate the minimum volume of oxygen

that is required for the complete combustion

of a mixture of 20cm3 of CO and 25cm3 of

hydrogen.

A. 45 cm3

B. 22.5cm3

C. 20 cm3

D. 10 cm3​

Answers

The answer would be A.
Hope this helps

Which two particles are found in an atom's nucleus?
O A. Neutrons
O B. Electrons
O C. Protons
O D. Isotopes

Answers

Answer:

protons and neutrons so A and C

The answer to this question is A and C.

Question 4
Volume is what type of physical property?

Answers

I think it would be oxygen

4. Do you think the distribution of elements 10 billion years from now
will be different than it is today? Why or why not?

Answers

Answer:

yes

Explanation:

everything will change

The following initial rate data are for the reaction of nitrogen dioxide with carbon monoxide:
NO2 + CO --> NO + CO2
Experiment [NO2]o, M [CO]o, M Initial Rate, Ms-1
1 0.374 0.300 8.39×10-2
2 0.374 0.600 8.39×10-2
3 0.749 0.300 0.337
4 0.749 0.600 0.337
Complete the rate law for this reaction in the box below.
Use the form k[A]m[B]n , where '1' is understood for m or n and concentrations taken to the zero power do not appear. Don't enter 1 for m or n
Rate= ________________
From these data, the rate constant is _________ M-1s-1.

Answers

Answer:

7.47 × 10^-1 M-1 s-1

Explanation:

Using the form k[A]^m[B]^n we arrive at the fact that the rate constant of the reaction can be written in the form;

Rate = k[NO2] [CO] where both m and n =1

We can use data from any of the experiments to establish the rate constant hence;

From experiment 1

[NO2] = 0.374M

[CO] = 0.300 M

R= 8.39 × 10^-2

Hence k =8.39 × 10^-2 / [0.374] [0.300]

k= 7.47 × 10^-1 M-1 s-1

which is not possible sign of chemical change
A:color change
B:light given off
C:heat given off
D:a change of state

Answers

Answer:

A. color change

Explanation:

changing the color of a metal does not change its physical properties.

hope it helps.

How is volume calculated given mass and density? (4 points)
A. Sum of mass and density
B. Mass divided by density
C. Mass multiplied by density
D. Difference of mass and density

Answers

It’s mass divided by volume. A helpful thing to use is the triangle of power where the M (mass) is on top and the D(density) and v(volume) is on the bottom.

Question 15
4 pts
Using the equation:
HgO --> Hg + O2
If 7.543 grams of HgO decompose, how many grams of oxygen are formed?

Answers

Answer:

1.184 g

Explanation:

Lmk if u need anything to be explained

What is a hypothesis? O a part of the scientific method that is not necessary a specific and testable question O the variables I observe during the experiment HELP HELP PLS PLS PLS HELP NoW NowWWwWw I'll mark u BRAINLIEST!!!!!!!!​

Answers

a testable question

What is the electron geometry of PF3?

Answers

Answer:

PF3 has a trigonal pyramidal molecular geometry.

Explanation:

PF3 has four regions of electron density / electron clouds around the central P atom. The regions of electrons make a tetrahedral arrangement with a bond angle of 109.5°. Only three regions of electrons are bonding and one is non-bonding, so the overall shape is trigonal pyramidal.

The electron geometry of [tex]PF_{3}[/tex] is trigonal pyramidal.

What are the characteristics of trigonal pyramidal geometry?In chemistry, a trigonal pyramid is a molecular shape that resembles a tetrahedron and has one atom at the top and three at the corners of the base (not to be confused with the tetrahedral geometry). The molecule belongs to the point group [tex]C_{3v}[/tex] when all three of the atoms in the corners are the same. The pnictogen hydrides ([tex]XH_{3}[/tex]), xenon trioxide ([tex]XeO_{3}[/tex]), the chlorate ion, [tex]ClO^{-} _{3}[/tex], and the sulfite ion, [tex]SO^{-2} _{3}[/tex] are some molecules and ions with trigonal pyramidal structure. Trigonal pyramidal-shaped molecules are sometimes referred to as sp3 hybridized in organic chemistry.Trigonal pyramidal is a molecular shape formed when three bonds and one lone pair exist on the central atom of the molecule. Sp3 hybridization occurs at the central atom of molecules with tetrahedral electron pair geometries. Ammonia (NH3) is a pyramidal trigonal molecule.

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