Answer:
In order to take steps by humans for controlling the change in climate.
Explanation:
It is important that scientist find out the change which occurs in the climate with the passage of time by performing experiments and also repeat the experiments in order to verify their findings. Due to these experiments, scientists also find out the reasons behind of climate change which enable us to take steps in preventing the change that occurs in the environment. it is also important for scientists to be able to explain how they know that climate has changed over time in order to explain that he is not assuming or making predictions, he has to provide evidence for his statement which is only be possible through experiments.
What happens to the total mass of a substance undergoing a physical change
Answer: It stays the same
Explanation:
Answer: it stays the same (A)
Explanation:
did the test online got 100%
This is how fluorine appears in the periodic table. A green box has F at the center and 9 above. Below it says fluorine and below that 19.00. A blue arrow points to 9. What information does "9” give about an atom of fluorine? Select three options. the atomic number the atomic mass the number of protons the number of electrons the number of neutrons
Why does diamond not conduct electricity
Answer: no free electrons
Explanation: Diamond is very hard due to the strong covalent bonds and rigid tetrahedral 3d arrangement. It does not conduct electricity, as there are no electrons free to move and carry charge through the structure.
Select all statements that are true for Sn1 reactions. (a) Formation of the carbocation is the rate-determining step (RDS) (b) The reaction rate depends upon the concentration of both the nucleophile and the electrophile (c) Reactions at chiral carbons proceed with inversion of stereochemistry (d) None of these statements are true for Sn1 reactions (e) Carbocation rearrangements are never observed
Answer:
(a) Formation of the carbocation is the rate-determining step (RDS)
(c) Reactions at chiral carbons proceed with inversion of stereochemistry
Explanation:
SN1 reactions arenucleophilic substitution reactions in which the rate determining step is unimolecular.
The formation of a carbocation is the rate determining step. This depends on the electrophilicity of the leaving group. Thus the SN1 reaction mechanisms is dependent on the electrophile and not the nucleophile.
Polar and acidic solvents which can assist in the formation of the carbocation speeds up the rate determining step.
If the formation of carbocation occurs at a chiral center, both retention and inversion of stereochemistry are likely to occur.
Therefore, the correct options are A and C.
What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?
Answer:
39
Explanation:
Total protons + total neutrons = mass number
Calculate the percentage of all elements in Fel(OH)3
Please help, I will mark the answer with brainlist...
Answer: 30.06% is your answer.
I hope this helps.
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Why does the presence of lone pairs contribute to the polarity of a water molecule
Explanation:
They allow the bonds between oxygen and hydrogen to be single. They increase the partial positive charge on the oxygen atom. They counter the uneven pull on electrons between the atoms.
what will happen if we burn carbon monoxide In a closed room??
Answer:
the carbon monoxide will release blue fumes
Two boxes need to be moved into storage. Jamal and Jude each want to move a box. The force of gravity on both the boxes is 50 N. Jamal is lifting with a force of 60 N, and Jude is lifting with a force of 45 N. Which best describes the movement of the boxes? Jamal moved his box to storage, but Jude could not move his. Jamal and Jude can successfully move each box into storage. Jamal could not move his box to storage, but Jude could. Neither Jamal nor Jude could move the boxes into storage.
Answer: 80
Explanation:
Answer:
Jamal moved his box to storage, but Jude could not move his.
Explanation:
The force they exert needs to be higher than the force of gravity in order for them to move the boxes. Jamal's force is 60N, which is 10N above the force of gravity on the box, which is 50N. However, Jude's force is only 45N and that is lower than 50N, so he won't be able to move the box while Jamal can.
A 10.0 g sample of an unknown liquid is vaporized at 120.0°C and 5.0 atm. The volume of the vapour is found to be 568.0 mL. The liquid is determined to be made up of 84.2% carbon and 15.8% hydrogen. What is the molecular formula for the liquid?
Answer:
molecular formula of liquid = C₈H₁₈
Explanation:
First we determine the empirical formula of the liquid:
Number of moles of each element present in the liquid = % mass / molar mass
For Carbon, (molar mass = 12.01 g/mol) : 84.2/12.01 =7.011 moles
For Hydrogen (molar mass = 1.01 g/mol) : 15.8/1.01 = 15.643
Simplest mole ratio of the elements, C : H is given by:
C = 7.011/7.011 = 1.0
H = 15.643/7.011 = 2.23
Multiplying through with 5, C:H = 5:11
Therefore, empirical formula is C₅H₁₁
The molecular mass of the liquid is next determined:
Using PV = nRT to find the number of moles of the liquid present
P = 5.0 atm; V = 568.0 mL = 0.568 L; R = 0.082 L*atmmol⁻¹ K⁻¹; T = 273 + 120 = 393 K
n = PV/RT = (5*0.568)/0.082*393
n = 0.088 moles
Molar mass of liquid = mass/no of moles = 10.0 g/ 0.088 moles = 113.63 gmol⁻¹
Molecular formula = n(empirical formula)
Molar mass of empirical formula, C₅H₁₁ = 71 gmol⁻¹
n = molecular mass/empirical mass = 113.63/71 = 1.6
Therefore, molecular formula = 1.6*(C₅H₁₁) = C₈H₁₈
An empty graduated cylinder weighs 55.26 g. When filled with 50.0 mL of an unknown liquid, it weighs
92.39 g. The density of the unknown liquid is:
Answer:
.743 g/mL
Explanation:
Hopefully this helps :)
Match each element to the correct description of its usual behavior in a chemical reaction.Silicon (Si)Argon (Ar)Sodium (Na)Will lose electrons
Answer:
Sodium (Na) — Will lose electrons
Silicon (Si) — Will lose electrons
Argon (Ar) — No reaction
Hope this helps.
an 80kg skateboard moving at 3m/s pushes off with her back foot to move faster. If her velocity increases to 5 m/s, what is her change in kinetic energy as a result
If you wanted to perform a controlled experiment to test the effect of temperature on the pressure of a bicycle tire, which of the following would be necessary?
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Answer: 25.0 L
Explanation:
For this problem, we will need to use Boyle's Law.
Boyle's Law: P₁V₁=P₂V₂
Since we are looking for V₂, we can rewrite the equation.
V₂=P₁V₁/P₂
The pressure should be in atm, so let's convert kPa to atm.
P₁=100 kPa=0.99 atm
P₂=200 kPa=1.97 atm
Now that we know the pressure in atm, we can plug it into the equation and solve.
[tex]V_{2} =\frac{(0.99 atm)(50.0L)}{1.97atm}[/tex]
[tex]V_{2} =25.0 L[/tex]
A base has a molarity of 1.5M w.R.T the hydroxyl ion concentration. If 7.35 cm3 of this base is taken and diluted to 147 cm3, then what is the concentration of the hydroxyl ion.
Answer:
0.077M is the concentration of the hydroxyl ion
Explanation:
Dilution factor is the ratio between the aliquot that is taken of a solution and the total volume of the diluted solution.
For the problem, dilution factor is:
7.53cm³ / 147cm³ = 0.05122
To obtain molarity of a diluted solution you must multiply dilution factor and initial molarity of the solution, thus:
1.5 M × 0.05122 = 0.077M is the concentration of the hydroxyl ion
What is the function of these organelles?
endoplasmic reticulum:
Golgi body:
mitochondrion:
ribosome
Answer:
endoplasmic reticulum:
✔ helps in the production and movement of materials
Golgi body:
✔ packages and distributes materials in and out of cell
mitochondrion:
✔ supplies energy that the cell uses
ribosome:
✔ produces proteins for the cell
Explanation:
I did it on Edge
The function of endoplasmic reticulum is it helps in production and movement of a material.
What is endoplasmic reticulum?Endoplasmic reticulum is defined as a network of membranous tubules present within the cytoplasm of a eukaryotic cell.
It is one of the important organ of human body system which helps us in production and movement of material from one body part to another.
Golgi body helps in packaging and distribution of material in and out of cells.
Mitochondrion supply the energy to the cell. It is called as a power house of cell.
Ribosome helps to produce protein for the cell. It is called as protein factory.
Thus, the function of endoplasmic reticulum is it helps in production and movement of a material.
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In which state of matter does heat travel fastest and slowest?
Answer:
Heat travels faster in solids.
Heat travels slower in gases.
Explanation:
The state of matter in which heat travels in fastest way is solid and in gaseous state heat travels in slowest way.
What is heat transfer?Heat transfer is a process in which heat can travel from one body to another body or from high temperature to low temperature.
In solid state heat will travel in the fastest way because molecules are arranged very close to each other and heat will travel through conduction process. And in gaseous state heat will travel with slowest way as molecules are arranged in very distance.
Hence in solid, heat travels in fastest way and in gases heat travels in slowest way.
To know more about heat conduction, visit the below link:
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The pressure exerted by 0.002 moles of a gas in a 500 mL container at 25oC is:
Answer:
0.1715 atm
Explanation:
We use the Ideal gas equation to calculate this
Mathematically;
PV = nRT
rearranging, we have
P = nRT/V
from the question, we have
n = 0.002 moles
R = 0.082
T = 250 = 250 + 273 = 523 K
V = 500 ml = 500/1000 = 0.5 L
Plugging the values we have;
P = (0.002 * 0.082 * 523)/0.5
P = 0.1715 atm
According to solubility rules, which of the following compounds is soluble in water?
A. Na Coz
B. BaSO4
O C. Ca(NO3)2
D. K3PO4
Answer:
Na2CO3
Explanation:
Na2CO3 is a compound soluble in water. So the correct option is A.
What are solubility rules?
The common ionic solids' solubility laws are as follows. When two rules seem to conflict with one another, the prior rule is used.
Group I element salts (Li+, Na+, K+, Cs+, and Rb+) are soluble. The few exceptions to this rule are rare. Ammonium ion (NH4+) salts are also soluble in water.Nitrate ion (NO3-) salts are often soluble.In general, salts containing Cl, Br, or I are soluble. Ag+, Pb2+, and (Hg2)2+ halide salts are significant exceptions to this norm. PbBr2, Hg2Cl2, and AgCl are hence insoluble.Silver salts are often insoluble. Most silver salts are insoluble, with the exception of AgNO3 and Ag(C2H3O2).Sulfate salts are often soluble. This rule has some notable exceptions, such as CaSO4, BaSO4, PbSO4, Ag2SO4, and SrSO4.The majority of hydroxide salts are hardly soluble. Group I element hydrate salts are soluble. Group II elements (Ca, Sr, and Ba) have soluble hydrate salts. Transition metal and Al3+ hydrate salts are insoluble. Fe(OH), Al(OH), and Co(OH)2 are so insoluble.The majority of transition metal sulfides, such as CdS, FeS, ZnS, and Ag2S, are very insoluble. Sulfides of lead, antimony, bismuth, and arsenic are also insoluble.Many times, carbonates are insoluble. Group II carbonates, including CaCO3, SrCO3, and BaCO3, as well as FeCO3 and PbCO3, are insoluble.Most of the time, chromates are insoluble. PbCrO4 and BaCrO4 are examples.Many phosphates, like Ca3(PO4)2 and Ag3PO4, are insoluble.Many fluorides, including BaF2, MgF2, and PbF2, are insoluble.
Therefore, the correct option is A
Read more about solubility, here
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What takes place in a cell's mitochondria ?
A.cellular respiration
B.DNA replication
C.protein synthesis
D.photosynthesis
I NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
c
Explanation:
the mitochodria is the protien power house of the cell
How many moles are in 1.5L of 0.40M Na2SO4?
Answer:
0.60 moles of Na₂SO₄
Explanation:
Molarity is an unit of concentration defined as the ratio between moles of solute and liters of solution.
A solution of Na₂SO₄ 0.40M contains 0.40 moles of solute (Na₂SO₄) per liter of solution.
As you have 1.5L of solution, moles of Na₂SO₄:
1.5L × (0.40mol / L) = 0.60 moles of Na₂SO₄
Which of the following statements are true? Significant figures in a measurement are all measured digits, and one estimated digit None of the above Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements
Answer: Significant figures in a measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy or precision is known as significant digits.
The significant figures of a measured quantity are defined as all the digits known with certainty and the first uncertain or estimated digit.
Rules for significant figures:
1. Digits from 1 to 9 are always significant and have infinite number of significant figures.
2. All non-zero numbers are always significant.
3. All zero’s between integers are always significant.
4. All zero’s preceding the first integers are never significant.
5. All zero’s after the decimal point are always significant.
The true statements are
Significant figures in measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
The following information should be considered:
The figures in a number that express the value or the magnitude of a quantity is known as significant digits.The significant figures of a measured quantity refers to all the digits known with certainty.Learn more: https://brainly.com/question/1979431?referrer=searchResults
How are industrial and agricultural pollution similar?
Answer:
Both of them are polluting the environment. Industrial pollution is the pollution caused from industries and it can be in different forms such as water waster or air pollution. Agricultural pollution is caused from plants or crops that are grown by the farmers. For example, pesticides that may ruin the soil and is dangerous for our environment.
Explanation:
15. Calculate the hydrogen ion concentration of a
solution whose pH is 2.4
A 3.6 x 0.01
B 2.5 x 0.0001
C 2.5 x 0.01
D 7.0 x 0.01
Answer:
Explanation:
pH = − log [H+] , we can solve for [H+] as,
− pH = log [H+] ,
[H+] = 10^−pH,
so PH =2.4 in you case is
[H+] = 10^-2.4 =0.00398
The option are not correct it looks
. Act 20 g Ca (M = 40g / mol) with H2SO4 diluted within 10 seconds. What will be the rate of hydrogen formation in mol / sec. please
Answer:
Rate of hydrogen formation is 0.05 mole per second
Explanation:
Firstly, we write the equation of reaction.
When alkali earth metals react with dilute mineral acid, the reaction is vigorous with the production or evolution of hydrogen gas as a result of the displacement of the hydrogen from the acid by the metal. This is one of the basic reactions of mineral acids
Ca + H2SO4 ——> CaSO4 + H2
Looking at the reaction, 1 mole of calcium gave 1 mole of the hydrogen gas
What we do now is to calculate the number of moles of calcium produced by 20g of Ca
Mathematically;
number of moles = mass/atomic mass
number of moles of calcium is thus
20/40 = 0.5 moles
Now, if 1 mole of calcium produced 1 mole of the gas
Definitely, 0.5 mole of calcium will produce 0.5 mole of the gas
So the rate of gas formation would be 0.5/10 = 0.05 mole/second
The energy from 0.015 moles of octane was used to heat 250 grams of water. The temperature of the water rose from 293.0 K to 371.2 K. What is the enthalpy of combustion of octane? The specific heat capacity of water is 4.18 J/K g.
A. -5448 kJ/mol
B. 1226 kJ/mol
C. -1226 kJ/mol
D. 293.25 kJ/mol
Answer:
A.) -5448 kJ/mol
Explanation:
I got it correct on founders edtell
calculate the ph and poh of a 0.0032 M solution of nitric acid NHO3
Answer:
HNO3 ->NO3²- + H+
Concentration of H+ ions= 0.0032M
pH = - log[ H+]
= - log (0.0032)
= 2.49
pH + pOH = 14
pOH = 14 - pH
= 14 - 2.49
= 11.51
pH = 2.49 and pOH = 11.51
Hope this helps.
Which process occurs at each link in a food chain?
Some Energy is released into the environment as heat
Explanation:
describes the forces that exist
between a liquid and different
molecules,
A Adhesion
B. Repulsion
C. Condensation
D. Cohesion
98-2000 Anths Charpentine A Nights Arsenal
Answer:
i just answered this and its a
Explanation:
