Answer:
Explanation:
It is necessary to run TLC in a closed container and have the interior saturated with the solvent vapor to ensure maximum resolution between components and to prevent solvent evaporating off. If the solvent evaporates off, the Rf value would be lower than the expected value.
A test tube is filled with water and a green plant called elodea.
Answer: The bubbles produced are most likely due to oxygen.
Explanation:
Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
The balanced chemical reaction for photosynthesis is:
how many atoms are there in 1.25 moles of Zn?
Answer:
7.53×10^23
Explanation:
i dont know how
Answer:
There are 6.25×10²³ atoms in 1.25 moles of Zn
When the skydiver is falling at a constant velocity after the parachute is open, what is their acceleration?
Answer:
Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward. ... The skydiver thus slows down. As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.
When the skydiver is falling at a constant velocity after the parachute is open, acceleration is zero.
The acceleration of the skydiver will be zero shortly after the parachute opens, but we can not call it as “acceleration due to gravity”.It's the acceleration due to gravity and air resistance together, and the forces cancel each other out to give an acceleration of zero.Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward.Learn more:
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A metallic bond can exist between atoms that have low ionization energies and
low electronegativities. Such atoms are of ___________
elements,
Answer: The elements that have the lowest electronegativity are the VIII A elements or noble gases. These elements have a theoretical electronegativity of zero. These elements are stable in their electron configuration there is not force moving the noble gases to gain any electrons.
Explanation:
an increase in enzyme or substrate concentration will
Answer: It will increase the rate of reaction
Explanation:
An increase in enzyme or substrate concentration will increase the rate of reaction.
What is an enzyme?An enzyme is a biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell.
Initially, an increase in substrate concentration leads to an increase in the rate of an enzyme-catalyzed reaction. As the enzyme molecules become saturated with substrate, this increase in reaction rate levels off.
The rate of an enzyme-catalyzed reaction increases with an increase in the concentration of an enzyme.
Hence, an increase in enzyme or substrate concentration will increase the rate of reaction.
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a sample of double-stranded dna contains 42% cytosine. approximately what percent of the nucleotides in this sample will be thymine?
Answer:
8% thymine
Explanation:
The percent of thymine in the given sample of the DNA will be equal to 8 %.
What is the structure of DNA?DNA, according to Chargaff, is composed of nucleotide subunits. These nucleotides are linked through two or more hydrogen-bonded to one another to form the double-stranded molecule of DNA.
The nucleotides found in the DNA molecule are Adenine, Thymine, Cytosine, and Guanine. Guanine (G) pairs with Cytosine (C) while Adenine (A) pairs with Thymine (T).
According to Chargaff's rule, the amount of Adenine is equal to that of Thymine in a DNA molecule and the same applies to Guanine and Cytosine. We can consider that the total amount of nucleotides equals 1 or 100%.
[tex]A + T + G + C = 100\%[/tex]
If Cytosine is 42 % of the DNA sample, this means that guanine will also be 42%.
G + C = 42 + 42 = 84%
A + T = 100% - 84 % = 16%
This means that Adenine and Thymine amount to 16 %. The amount of each nucleotide will be 16% ÷ 2 = 12% i.e. A = T = 8 %
Therefore, the percent of thymine in the given sample of the DNA will be 8 %.
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What are the atoms of Fe(SCN)3
Answer:
55.845
Explanation:
yep
What happens to the wavelength and frequency of light as you move from red to violet?
A. Both wavelength and frequency increases.
B. Both wavelength and frequency decreases.
C. Wavelength decreases and frequency increases.
D. Wavelength increases and frequency decreases.
1. Imagine doing the same virtual experiment using wood as the bottom material, instead of glass or water. Predict how the light would interact with the wood.
The wood can't do the same function as done by the water and glass in the same virtual experiment due to its different chemical composition.
The light will not pass through the wood due to its translucent behaviour that prevents light to pass through it as compared to water and glass which are transparent materials and light can easily pass through it.
So using wood as a bottom material instead of glass and water will not perform the same function as perform by water and glass in the same virtual experiment so we can conclude that wood can't perform the same function in the experiment.
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Question 8 (2 points)
(02.02 LC)
A mixture contains nuts, drink mix, orange slices, and berries. Which part of this mixture is soluble in water? (2 points)
а
Berries
Ob
Drink mix
Ос
Nuts
Od
Orange slices
Question 9 (2 points)
(02.02 LC)
which of the following dissolve in water? (2 points)
Answer:
B. Drink Mix
Explanation:
Assuming the drink mix is something like Kool-aid, it is soluble in water. The rest are solids that cannot be dissolved in water.
Help me have no frewnds
how to make slime without borax or contact solution or laundry detergent or cornstarch
How would one convert 6 pounds to ounces (16 oz = 1b)?
Answer:
D.
Explanation:
I just got it right in the test :)
6) Which of the following would travel the farthest in column chromatography?
a. CH3CH2CH2COOH
b. C6H6
c. CH3OH
d. C8H18
The answer would be C8H18, or octane. Column chromatography is a separation technique that works off of polarity. The stationary phase, in column chromatography, are non-modified silica gels. Silica gels are normally polar. This means the solvent that will elute first are non-polar molecules...then polar molecules. The polar silica gels have a stronger interaction with polar molecules like CH3OH, and therefore will lag the solvent. Additionally, as you decrease the carbons, in hydrocarbons, the molecule becomes more polar. This is not C6H6 isn't the answer and octane is.
C8H18 will travel the farthest in column chromatography.
Chromatography is know as a process of analyzing and purifying organic compounds.There are different forms of chromatography. there is the column chromatography, Gas chromatography etc.
Alkanes are known to be least polar and as such would travel farthest into the mobile phase of the four functional groups. C8H18 belongs to the alkanes family.
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Which of the following is an example of chemical energy being used?
(A) Battery in a flashlight
(B) Ice melting
(C) Riding a bicycle
(D) Mercury rising in a thermometer
Answer:
(A) Battery in a flashlight
Explanation:
Because the chemicals in the battery are being converted to light and heat energy from the bulb!
Answer: D
Explanatione: I hope this helped :)
Problem: Janna, a student of a chemistry class, told her friend that she learnt in class that bottled water is not pure. Kim, her best friend, refused to believe Janna, referring to phrases on the label of the bottle.Help me
Answer:
The bottle is labeled pure so it probably is pure.
Explanation:
The distance from one crest to the next crest is ____
Answer:
Wavelength is the distance from one crest to another, or from one trough to another, of a wave (which may be an electromagnetic wave, a sound wave, or any other wave). Crest is the highest point of the wave whereas the trough is the lowest.
Explanation:
Hope this helps!
Answer:
Wavelength!
Explanation:
Hope this helps, please give me brainliest. ;)
which scientist also arranged the elements by increasing atomic mass and used the pattern to predict the existence of elements yet to be discovered?
the smallest unit of matter that retains the properties of that matter is
Answer:
here is your answer.
Explanation:
atom.
thanks for asking:)
Help me Plz, I am really confused
Explain error and how it can impact your results from an experiment.
Answer:
Random errors will shift each measurement from its true value by a random amount and in a random direction. These will affect reliability (since they're random) but may not affect the overall accuracy of a result.
6. Which of the following is a binary compound?
a. CaCO3
b. CuSO4
c. H2O
d. Pb(NO3)2
Answer:
The answer to your question is c. H2O
Explanation:
a. CaCO3 ----> Calcium Carbonate is obviously not a binary compound because it contains more than two elements.
b. CuSO4 ----> CuSO4 stands for copper(II) sulfate. Sulfate is the polyatomic ion SO4 -2.
c. H2O ----> Binary molecular compounds are composed of only two elements. Examples are H2O, NO, SF6 etc.
d. Pb(NO3)2 ----> Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2.
I hope this helps and have a great day!
how can you tell whether a substance is a binary compound
Given what we know, we can confirm that a compound will be a binary compound if it contains both a metal and a non-metal element.
Why does this combination form binary compounds?The reason for this is that metals will be able to donate electrons thanks to their chemical properties. Meanwhile, non-metal elements will seek to receive electrons to become more stable.For these reasons, metals and non-metals will come together to create covalent bonds, and thus, binary compounds.Therefore we can confirm that since a metal will donate its electron to a non-metal element to form covalent bonds, we will know if the compound is binary or not based on the presence of a metal and a non-metal.
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Aluminum is manufactured using electrolysis. Carbon electrodes are used. Describe the nature of the electrolyte.
At which electrode is the aluminum produced?
Answer:
The traditional electrolyte for aluminium electrolysis is based on molten cryolite (Na3AlF6), acting as solvent for the raw material, alumina (Al2O3).Metals are found in ores combined with other elements. Electrolysis can be used to extract a more reactive metal from the ore.
Aluminum can and is used as both anodes and cathodes in electrochemical cells, but there are some peculiarities to using it as an anode in aqueous solutions. As you note, aluminum forms a passivating oxide layer quite readily, even by exposure to atmosphere. In an aqueous solution, if the potential is high enough, OH− and O2− are generated at the anode, which can then react with the aluminum to produce aluminum oxide. Al^3+ can also be generated directly. The electric field will draw the anions through the growing aluminum oxide layer towards the aluminum surface and the Al^3+ towards the solution, making the oxide layer grow both away from the electrode surface and into the surface of the electrode. In this way, coatings thicker than the normal passivation in air can be produced. However, aluminum oxide is a good electrical insulator, thus if a dense non-porous layer is grown, it will become impossible to pass current through it and growth will stop, leaving a relatively thin oxide layer (this is how the dielectric layers in electrolytic capacitors are made). This is the normal behaviour in aqueous solutions at near-neutral pH (5–7).
However, if a thick aluminum oxide layer is desired (e.g. to produce coatings on aluminum parts for dying or durability), maintaining porosity is necessary to avoid completely blocking access to the surface. One technique that is commonly used is using a low pH solution, which tends to redissolve some of the oxide and neutralize some of the formed OH−, leaving pores in the oxide layer through which the ions can travel and continue to react. These pores also give a good structure to retain dyes or lubricants, but generally need to be sealed after to protect against corrosion.
Why do you think the term ionic is used to describe compounds formed from a metal element and a nonmetal element?
Answer:
All compounds form when atoms of different elements share or transfer electrons. Compounds in which electrons are transferred from one atom to another are called ionic compounds.
Explanation:
Because the positive and negative charges cancel out, an ionic compound is neutral in charge.
hello how to draw the electron dot structure of H2S and F2?
Explanation:
1. Attachment
Electron dot structure of H2S (hydrogen sulfide)
2. Attachment
Electron dot structure of F2 (Fluorine).
!! Help!! Which statement accurately describes malleability?
Answer:
B
Explanation:
Malleability describes a substance's ability to deform under pressure and heat
Examples: Gold, iron, aluminum, copper, silver, and lead. Gold and silver are highly malleable. When a piece of hot iron is hammered it takes the shape of a sheet.
Nitrogen gas is more abundant and I miss her than oxygen however nicer than to be converted into different forms to be used by many organisms bacteria are highly involved in this describe the role of a bacteria fixing nitrogen as he lives in Barclay with some plant species be nature find bacteria and see did you find bacteria in the nitrogen cycle
Answer:
who lives in Barclays what?? this makes no sense
Explanation
for 2.02
Control group: cricket frog population Reminder: The test variable is the item that is changing in this investigation. The outcome variable is the item that you are measuring in this investigation. The control group is the group in the experiment where the factors being tested are not applied. It allows scientists to set a baseline to compare the experimental groups that do have factors applied to them.
Test variable (independent variable):
Outcome variable (dependent variable):
Limiting factor- Food, Pollution, Predators.
Outcome variable (dependent variable): Cricket Frog (population)
Control group: Cricket Frogs in the Florida Everglades without changes in or manipulation of the population.
Viết các phương trình phản ứng dưới dạng phân tửvà ion thu gọn trong các trường hợp sau đây:a)CaCl2+ K2CO3b)Zn(OH)2+ KOH