The chemical reaction between the reagents luminol and bleach produces a brief flash of light. Which change would most likely make the light produced in the reaction last longer?
increasing luminol concentration
adding a catalysts
decreasing the quantity of both reagents.
decreasing the temperature
How much of the original amount of an isotope is present after a period of two half-lives?
A. Four times the original amount
B. One-fourth of the original amount
C. Twice the original amount
D. Half of the original amount
One-fourth of the original amount of an isotope is present after a period of two half-lives as each time the amount is reduced by half.
What is an isotope?Isotopes are defined as substances having same number of protons but different number of neutrons.Number of protons is characteristic for determining position of elements in the periodic table.
Since,all isotopes have the same number of protons and hence have same position.They have similar chemical properties as they have same number of electrons.
They find applications in the field of nuclear medicine and oil and gas research . There are 2 types of isotopes : stable and unstable
Unstable isotopes are radioactive and are called as radioisotopes.Some of these isotopes are man -made and hence also called as artificial isotopes.Every element has an isotope which is either man-made or natural .
Many properties of isotopes depend on mass which is measured in atomic mass unit. The difference in actual mass and mass number is called mass defect.
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Which of these describes why a stent is used?
A stent is a small mesh tube that holds open passages in the body, such as weak or narrow arteries.
Explanation:
To open an artery near the heart
just took the quiz
Nitrogen makes up what part of the air?
3/5
2/5
4/5
About 4/5.
Hope this helps.
Answer: c
Explanation:
What does the emission spectrum of a molecule show?
A. The energy the molecule absorbs as it undergoes a reaction to break down into its elements
B. The wavelengths of light a molecule gives off when an electron moves to lower energy levels
C. The wavelengths of light a molecule takes in when an electron moves to a higher energy level
D. The energy the elements give off as they undergo a reaction to form a molecule
Answer:
B. The wavelengths of light a molecule gives off when an electron moves to lower energy levels
What is microorganisms
Answer:
Technically a microorganism or microbe is an organism that is microscopic. The study of microorganisms is called microbiology. Microorganisms can be bacteria, fungi, archaea or protists. The term microorganisms does not include viruses and prions, which are generally classified as non-living.
Which of the following is an example of commensalism?
Answer: A tick on a deer
Explanation:
because commensalism is a type of symbiotic relationship in which one species benefits, while the other species is neither harmed nor helped
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An example of commensalism is tick on a deer. Therefore, option A is correct.
What is commensalism ?Another sort of symbiotic interaction is commensalism, in which one organism benefits and the other does not in any way suffer. Golden jackals will pursue tigers as they hunt in order to consume the tigers' leftovers.
The term "commensalism" is derived from the word "commensal," which in human social interaction refers to "eating at the same table," and which itself is derived through French from the Medieval Latin term "commensalis," which refers to "sharing a table," from the prefix com-, which means "together," and mensa, which refers to "table" or "meal."
The simplest definition of commensalism is that it is a form of symbiosis in which one organism gains while the other neither gains nor suffers harm. The three primary forms of commensalism are phoresy, metabiosis, and inquilinism.
Thus, option A is correct.
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picture below
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1. [tex]\sf \bf {\boxed {\mathbb {Evaporation}}}[/tex] - The changing of liquid to a gas.
2. [tex]\sf \bf {\boxed {\mathbb {Automobile}}}[/tex] - The major source of pollution.
3. [tex]\sf \bf {\boxed {\mathbb {Greenhouse \:effect}}}[/tex] - Carbon dioxide and water vapor trapping heat given off by Earth.
4. [tex]\sf \bf {\boxed {\mathbb {Ozonosphere}}}[/tex] - Layer absorbing ultraviolet rays.
5. [tex]\sf \bf {\boxed {\mathbb {Condensation}}}[/tex] - The changing of a gas to a liquid.
6. [tex]\sf \bf {\boxed {\mathbb {Ionosphere}}}[/tex] - Layer responsible for reflecting radio waves.
7. [tex]\sf \bf {\boxed {\mathbb {Troposphere}}}[/tex] - The layer in which weather changes.
[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{❦}}}}}[/tex]
Answer:
1. Evaporation :- The changing of a liquid to a gas.
2. Automobile :- The major source of pollution.
3. Greenhouse effect :- Carbon dioxide and water vapour trapping heat gives off by Earth.
4. Ozonosphere :- Layer absorbing ultraviolet rays.
5. Condensation :- The changing of gas to a liquid.
6. Ionosphere :- Layer responsible for reflecting radio waves.
7. Troposphere :- The layer in which weather changes.
Which is a property of all acids?
A. They increase the OH^- concentration in solution.
B. They contain OH^- ions.
C. They contain H3O^+ ions.
D. They increase the H^+ concentration in solution.
Acids increase the [tex]H^+[/tex] concentration in solution. Therefore, the correct option is D.
One of their essential characteristics is the ability of all acids to increase the concentration of H+ ions (protons) in a solution. Acids are chemicals that when dissolved in water add protons to the solution. As a result of this proton donation, the amount of [tex]H^+[/tex]ions in the solution increases, thereby lowering the pH. It is important to remember that not all acids contain[tex]H_3O^+[/tex] ions directly; Instead, [tex]H^+[/tex] ions can react with water molecules to generate [tex]H_3O^+[/tex] ions (hydronium ions).
Therefore, the correct option is D.
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what do you mean by chemical reaction
Answer:
Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products.
A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
Chemical reactions are an integral part of technology, of culture, and indeed of life itself. Burning fuels, smelting iron, making glass and pottery, brewing beer, and making wine and cheese are among many examples of activities incorporating chemical reactions that have been known and used for thousands of years. Chemical reactions abound in the geology of Earth, in the atmosphere and oceans, and in a vast array of complicated processes that occur in all living systems.
Explanation:
hope it help
plss brainlys me
Answer:
Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products
Explanation:
Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
12. If a reaction is exothermic,
a) It takes more energy to break the bonds of the reactants than is released when the bonds in
the products are formed
b) More energy is released when the bonds in the products are formed than is used to break
the bonds in the reactants
c) The same amount of energy is used to break the bonds of the reactants as is
released when the bonds in the products are formed
d) The temperature goes down
Answer:
In the case of an exothermic reaction, the reactants are at a higher energy level as compared to the products, as shown below in the energy diagram. In other words, the products are more stable than the reactants. Overall Δ H ΔH ΔH for the reaction is negative, i.e., energy is released in the form of heat.
Explanation:
why elements with more than 20 protons always have a more neutrons than protons?
Answer:
Elements that have atomic numbers from 20 to 83 are heavy elements, therefore the ratio is different. The ratio is 1.5:1, the reason for this difference is because of the repulsive force between protons: the stronger the repulsion force, the more neutrons are needed to stabilize the nuclei.
Arrange the compounds in order of increasing entropy (S).
CH3OH(s)
CH3OH(l),
CH3OH(g),
CH3CH2OH(g)
CH3OH(s) > CH3OH (l) > CH3OH(g) > CH3CH2OH(g)
CH3OH(s) < CH3OH (l) < CH3OH(g) < CH3CH2OH(g)
3 Of 20
Answer:
CH3OH(s)<CH3OH(l)<CH3OH(g)<CH3CH2OH(g)
Explanation:
Entropy is defined as the degree of disorderliness of a system. The more orderly a system is, the more its entropy tends to zero.
Hence solid particles have the least entropy because solid particles do not translate. The entropy of liquid particles is greater than that of solid particles since liquid particles can translate. Gas particles have the highest entropy because gas particles move at a very high velocity owing to minimal intermolecular interaction.
Also, the heavier the molecules of a substance, the larger its molar entropy therefore, CH3CH2OH(g) exhibits the greatest entropy.
1
N
3
5
6
7
| 8 9 10
Which is evidence that a chemical reaction has likely occurred?
a liquid slowly losing volume
the formation of a precipitate
boiling water releasing steam
a change in the shape of a solid
Answer:
The new substance will need more energy to form its chemical bonds than the old substance will release. ... More energy will be released from the old substance than the new substance will need to form its chemical bonds.
Explanation:
This is the answer I got. Hope it's really helpful
Answer:
"Which is evidence that a chemical reaction has likely occurred?"
The correct answer would be,
B. the formation of a precipitate
Explanation:
Got it right on my test, have a great day!
calculate the volume of a 3.0 mol of oxygen, b 50.0g of hydrogen cloride gas at STP(molar volume of gas is 22.4dm³,molar mass of Hcl=36.5g)
Answer:
98L is the volume of the gas
Explanation:
To solve this question we need to find the moles of O2 + moles HCl. With these moles and PV = nRT we can find the volume as follows:
Moles O2: 3.0mol
Moles HCl:
50.0g * (1mol/36.5g) = 1.37 moles HCl
Total moles:
3.0mol O2 + 1.37 mol HCl = 4.37 moles
PV = nRT
V = nRT/P
Where V is volume in L, n are moles = 4.37mol, R is gas constant = 0.082atmL/molK, T is absolute temperature = 273.15K at STP, P = 1atm at STP
V = 4.37mol*0.082atmL/molK*273.15K / 1atm
V = 98L is the volume of the gas
Which method of separation would you use, if you want to collect.....A.Some sugar from a sugar solution? B.Rice grains, which have accidentally been mixed with flour? C.Some pure water from salty water?D.Some salt from salty water?E.Some clear water from muddy water?
Answer:
Explanation:
B.Rice grains, which have accidentally been mixed with flour
1.875mps into kilometers per hour
Answer:
6,75 kilometres per hour
What's the difference between a substance and a mixture
Answer:
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
Radhe Radhe❤
Answer:
A pure substance consists of only one element or one compound. Whereas, a mixture consists of two or more different substances which aren't chemically joined together.
What mass of sulfuric acid, H2SO4, is required to react with 3.27 g of potassium hydroxide, KOH? The products of this reaction are potassium sulfate and water.
Have both the unbalanced and balanced chemical equations.
Explain how to find the molar mass of the compounds.
Explain how the balanced chemical equation is used to find the ratio of moles
Explain how many significant figures your answer needs to have.
The numerical answer
Answer:
pa help din ako jan pleaseAnswer:
Don't plagiarize here.
Explanation:
Your online teacher knows that you are looking here for the answer!!!!
Given that the acceleration due to gravity is 10N/Kg, calculate the weight of the
Mass (Show all you're working)
Answer:
Weight = 500 Newton
Explanation:
Given the following data;
Acceleration due to gravity = 10N/Kg
Weight can be defined as the force acting on a body or an object as a result of gravity.
Mathematically, the weight of an object is given by the formula;
[tex] Weight = mg [/tex]
Where;
m is the mass of the object.g is the acceleration due to gravity.Note: In order to calculate the weight of a mass, it's required that the mass of an object or body is given.
However, in this particular question it was omitted in error and as such i would assume a value.
Let mass, m = 50 kgSubstituting into the formula, we have;
[tex] Weight = 50 * 10 [/tex]
Weight = 500 Newton
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
The molecules move more quickly and their average kinetic energy increases
The molecules move more bowly and their average kinetic energy decreases
The molecules move more quickly and their average kinetic energy decreases
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move slower than the temp of 50°c and their average kinetic energy decreases.
Explanation:
kinetic energy cannot increase as temperature is reduced. molecules will still move with reduced motion.
State the name(s) of the sub-atomic particle(s) that have/has a positive charge. Answer with the name of the particle(s) only.
A. Neurons
B. Protons
C. Electrons
Answer:
protons because they have the most positive charge
How many moles of NaOH are present in 22.0 mL of 0.140 M NaOH?
Answer:
Mole of NaOH = 0.00308 mole
Explanation:
From the question given above, the following data were obtained:
Volume = 22 mL
Molarity = 0.140 M
Mole of NaOH =?
Next, we shall convert 22 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
22 mL = 22 mL × 1 L / 1000 mL
22 mL = 0.022 L
Finally, we shall determine the number of mole of NaOH in the solution. This can be obtained as shown below:
Volume = 0.022 L
Molarity = 0.140 M
Mole of NaOH =?
Molarity = mole / Volume
0.140 = Mole of NaOH / 0.022
Cross multiply
Mole of NaOH = 0.140 × 0.022
Mole of NaOH = 0.00308 mole
Thus, 0.00308 mole of NaOH is present in the solution.
The atomic number and the mass number of 18 and 40. Write the information conveyed by this statement.
How many moles are in 89 grams of KCI
Answer:
The number of moles in 89 grams of KCl is approximately 1.193 moles
Explanation:
A mole of an element or compound, is the quantity of the element or compound that contains 6.022 × 10²³ molecules of the element or compound, such that the molar mass of one mole is dependent on the mass of each molecule of the element or compound that make up the 6.022 × 10²³ particles
The given parameters are;
The mass of the KCl = 89 grams
The Molar mass, MW, of potassium, K = 39.1 g/mole
The Molar mass, MW, of chlorine, Cl = 35.5 g/mole
Therefore, given that KCl, has one K and one Cl, per mole, we have;
The Molar mass, MW, of potassium chloride, KCl = (39.1 + 35.5) g/mole = 74.6 g/mole
[tex]The \ number \ of \ moles, n=\dfrac{Mass}{Molar \ mass, MW}[/tex]
Therefore, the number of moles of KCl in 89 g, 'n' is given as follows;
n = (89 g)/(74.6 g/mole) ≈ 1.193 moles
The number of moles in 89 grams of KCl, n ≈ 1.193 moles.
Equal mases of ethane and hydrogen are mixed in an empty container at 25 degree celcius.The fraction of the total pressure exerted by hydrogen is
Answer:
15/16
Explanation:
We need to find the number of moles of hydrogen and number of moles of ethane present.
Since we have the same mass, m for both substances, the number of moles of hydrogen, n = m/M where M = molar mass of hydrogen molecule
Since hydrogen is H₂, M = 2 × 1 g/mol = 2 × 1 g/mol = 2 mol.
n = m/M
n = m/2
Also, number of moles of ethane, n' = m/M' where M' = molar mass of ethane.
Since ethane is C₂H₆, M' = 2 × 12 g/mol + 6 × 1 g/mol = 24 g/mol + 6 g/mol = 30 g/mol
n' = m/M'
n' = m/30
The total number of moles of gas present is thus n" = n + n' = m/2 + m/30 = (15m + m)/30 = 16m/30
The mole fraction of hydrogen is thus number of moles of hydrogen/total number of moles = n/n" = m/2 ÷ 16m/30 = m/2 × 30/16m = 15/16
Also, since the partial pressure due to hydrogen, P = mole fraction × total pressure, P'
P/P' = mole fraction = 15/16
So, The fraction of the total pressure exerted by hydrogen is 15/16
Gas occupies 30 Liters at 2.0 atm pressure and 27° Celsius. How many moles of gas are present
How many grams are in 36.2 moles of Iron (I) fluoride?
Answer:
4084.808 grams (SigFigs: 4085 grams)
Explanation:
The molar mass of Iron fluoride is 112.84 g/mol.
To calculate the mass, multiply the molar mass by the number of moles.
36.2 mol * 112.84 g/mol = 4084.808 g
Convert to Sigfigs (if necessary):
4085 g
Answer:
The person above is correct
Explanation:
identify if it is mixture,compound or element
Answer:
12:35
Try it this way. egst11245
Answer:
A is mixture
B and C are compund
D and E are elements
F is also mixture
Here is a word equation for a chemical reaction.
copper oxide + sulphuric acid
---> copper sulphate + water
Write down everything that the word equation tells you about the reaction.
Explanation:
From the word equation, it shows that when copper oxide reacts with sulphuric acid, a double replacement reaction will occur, where copper and sulphate forms a bond with each other, and so do water.
The reaction of copper oxide with sulphuric acid to form copper sulphate and water can be written as follows: [tex]CuO + H_{2}SO_{4} \rightarrow CuSO_{4} + H_{2}O[/tex]
What is a balanced reaction?In a balanced chemical reaction all the reactants will be in a correct stochiometric ratios where, each elements have to be equal in number on both side of the reaction.
The given reaction is an example of double displacement reaction in which two species are displaced. Here, oxygen from copper oxide goes to water and sulphate group from sulphuric acid displace to copper sulphate.
This product of this reaction i.e., copper sulphate have cyan color and this reaction is exothermic. Thus, the balanced reaction can be written as follows;
[tex]CuO + H_{2}SO_{4} \rightarrow CuSO_{4} + H_{2}O[/tex]
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