Answer:chlorofluorocarbons (CFCs) could deplete Earth's atmospheric ozone layer, which blocks the sun's damaging ultraviolet rays. When the scientists reported their findings in 1974, CFCs were widely used as refrigerant gases and as propellants in aerosol sprays
Explanation:
PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means
Answer:
C.
Explanation:
Answer A is incorrect because a compound doesn't have to be made with only metals.
Answer B is incorrect because that is actually the definition of a pure element.
Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.
Answer D is incorrect because compounds cannot be separated by physical means.
Hope this helps :D
cual es la importancia de los solidos en la vida ?
Answer:
La comida es un sólido y no podemos vivir sin comida. Algunos sólidos son buenos conductores de calor y electricidad; otros son aislantes. Los sólidos se utilizan todos los días en la vida.
17. The name of the reaction that produces esters is
A. addition.
B. anionic initiated polymerization.
C. radical initiated polymerization.
D. dehydration
Answer:
the name of reaction that produces esters is dehydration.
How many Sodium (NA) Atoms are in Methylene?
Answer:
No Sodium(Na) in methylene
Explanation:
Methylene is an organic compound
A place where animals are protected in their natural habitat is called ------------------
answer is wildlife sanctuary
Answer:
a wildlife sanctuary
Explanation:
3. Determine the pH value for calcium hydroxide, Ca(OH), with concentration of
0.05 mol dm3. [pH + pOH = 14).
Explanation:
Ca(OH) is a base
pOH = -Log[OH]
[OH] = 0.05
pOH = -Log(0.05)
pOH = 1.3
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
pH = 12.7
Choose the answer that is not correct: RER is: Group of answer choices The ratio of carbon dioxide produced to oxygen consumed An indication of the percentage of carbohydrate metabolized An indication of the percentage of lipid metabolized An approximation of kilocalories obtained per liter of oxygen consumed An indication of calories consumed during anaerobic energy production
Answer:
An indication of calories consumed during anaerobic energy production
Explanation:
RER stands for respiratory exchange ratio, which is the ratio of the volume of carbon dioxide, CO₂, produced to the volume of oxygen, O₂ used in metabolism. RER is used in determining the respiratory quotient during aerobic exercise and rest, from which it can be determined if carbohydrate or fat is the source of fuel consumed in the production of energy for the body through metabolism
Therefore, the answer that is not correct is an indication of calories consumed during anaerobic energy production
I have no idea how to do this and need help
Answer:
60.55%
Explanation:
nO3=155/48
nO2 used: 3/2nO3=4.84375
percent yield: 4.84375/8=60.55%
Question 6 of 10 What is the function of mitochondria? O
A. The mitochondria use sugars as fuel to produce energy.
B. The mitochondria direct the cell's activities and hold its DNA.
C. The mitochondria surround the cell and control which materials come into and out of the cell.
D. The mitochondria use sunlight to produce sugars. SUBE
Answer:
A. The mitochondria use sugars as fuel to produce energy.Explanation:
The most prominent function of mitochondria is to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration and using sugar as fuel, and to regulate cellular metabolism .
3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.
Answer:
- 10.6° C
Explanation:
Given that,
In the aqueous sucrose solution,
Molality of the solution (m) = 5.7
Freezing point constant (K) = 1.86
To find,
The freezing point of the solution = ?
Method:
To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.
In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,
ΔT(change in temperature) = i * m * K (putting the given values)
= 1 * 5.7 * 1.86
= 10.6° C
Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.
What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?
The mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water is 29.7%.
What is mass percent ?Mass percent is a means to describe a component in a specific combination or to convey a concentration. The mass percentage used to describe the solution composition indicates the mass of solute contained in a given mass of solution.
To determine the mass percent of an element in a compound, we divide the mass of the element in one mole of the compound by the compound's molar mass and multiply the result by 100.
Given:
Number of moles = 0.64 moles
Moles of sodium fluoride = Given mass/molar mass
0.64 moles = Mass / 42
Mass = 26.88gram
Mass % = Mass of solute/ mass of solution × 100
= 26.88/90.48 × 100
= 29.7 %
Thus, 29.7 % is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water
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What is the name of this molecule?
H3C - C ≡ C - CH3
Answer: 1,2,3, or 4-butyne?
Explanation:
The given molecule is
H3C - C ≡ C - CH3
The numbering order is shown below:
H3C - C ≡ C - CH3
1 2 3 4
So, the alkyne group is in the second position.
The carbon chain has four carbons.
Hence, the IUPAC name of the given compound is:
2-butyne.
25. Production is a. Transformation b. Reduction c Consumption d. Valuation
Answer:
a
Explanation:
I think a is the answer because when you produce something you transform it's raw materials to a finished good.
I hope this helps
value of MA is always lesser thàn 1 why?
Answer:
because the load arm is greater than the effort arm. As we know that when the load arm is greater than the effort arm, the mechanical advantage will always be lesser than one, which results in gain in speed
How much heat is added if .0948g of water is increased in temperature by .728 degrees C?
.289 J
.803 J
1.46 J
.055 J
Answer:
0.289J of heat are added
Explanation:
We can relate the change in heat of a substance with its increasing in temperature using the equation:
q = m*ΔT*S
Where Q is change in heat
m is mass of substance (In this case, 0.0948g of water)
ΔT = 0.728°C
S is specific heat (For water, 4.184J/g°C)
Replacing:
q = 0.0948g*0.728°C*4.184J/g°C
q = 0.289J of heat are added
cho hỗn hợp gồm alcl3 và fecl3 trình bày cách tách từng muối riêng ra khỏi hỗn hợp
Answer:
ném NaOH vào thì th AlCl3 tan hết còn lại kết tủa Fe(OH)3 lần.
Lọc kết tủa riêng phần dung dịch tan riêng
Rồi Cho HCl vô lại là xong
Explanation:
Where does reduction occur in an electrochemical cell?
Answer:
The cathode is the electrode where reduction takes place.
so
reduction occur in Cathode in an electrochemical cell.
Answer: Cathode
Explanation:
.
Which statement best describes what happens as thermal energy from the
sun warms the pavement?
A. The thermal energy absorbed by the pavement is destroyed.
B. The thermal energy that is not absorbed by the pavement is
destroyed.
C. Some thermal energy is absorbed by the pavement, and some is
destroyed.
D. The thermal energy of the sun is transferred to the pavement.
Answer:
D
Explanation:
The correct answer would be that the thermal energy of the sun is transferred to the pavement.
Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.
When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.
The correct option is, therefore, D.
Chất tinh khiết là:
A. Có tính chất thay đổi
B. Có lẫn thêm vài chất khác
C. Gồm những phân tử đồng dạng
D. Không lẫn tạp chất
Answer:
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.
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The addition of solute particles into a solution causes:
A. the solvent particles to be attracted to the solute particles and to have less kinetic energy.
B. the solute particles to bump the solvent particles out of the solution, making it easier to boil.
C. the solute particles to form seed crystals and make the solution freeze more easily.
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Answer:
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Explanation:
The addition of solute particles results in an increased boiling point. As the solutes increases so does the energy inside as the solutes add and occupies more space near the surface of the liquid.which statement is generally true about CaCaI2 ?
Explanation:
"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.
PLZ HELP There are two main ways that organisms reproduce, or make more Individuals of their own kind. Which of the following is true of these two types of reproduction?
A. In one way, two parents are involved. In the other, there is only one parent
B. In reproduction that involves only one parent, the offspring are different from the parent. In reproduction that involves two parents, the offspring receive exact copies of the parents' DNA.
C. In both ways, offspring share characteristics with their parents but are not exactly the same. O
D. In both ways, all offspring are identical to each other but maji different from their parents.
Answer:
A
Explanation:
Two parents are involved in Sexual Reproduction but only one is involved in Asexual Reproduction.
What is the pressure in atm exerted by 1.8 g of H2 gas exert in a 4.3 L balloon at 27ºC? R = 0.821(L*atm) / (mol*K)
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The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
What is Ideal gas law ?The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Let's convert grams to moles (via molar mass).
Molar Mass (H₂) : 2 (1.008 g/mol)
Molar Mass (H₂) : 2.016 g/mol
1.8 grams H₂ 1 mole
---------------------- x ---------------------- = 0.893 moles H₂
2.016 grams
The Ideal Gas Law equation looks like this:
PV = nRT
In this equation,
P = pressure (atm) V = volume (L) n = moles R = Ideal Gas Constant (0.0821 L*atm/mol*K)T = temperature (K)After converting Celsius to Kelvin, you can put the given values into the equation and simplify to find the pressure.
P = ? atm R = 0.0821 L*atm/mol*K
V = 4.3 L T = 27 °C + 273.15 = 300.15 K
n = 0.893 moles
PV = nRT
P (4.3 L) = (0.893 moles) (0.0821 L*atm/mol*K)( 300.15 K)
P (4.3 L) = 22.0021
P = 5.12 atm
Therefore, The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm
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Which element will form In ion whose lonic radius is larger than its atomic radius?
(1) K
(2) F
(3) LI
(4) Mg
Answer:
Letter b so F
Explanation:
I hope this help
Explanation:
All five ions have an equal number of electrons and therefore share the same electron configuration. For example, a neutral calcium atom (Z=20) has 20 electrons; it loses two of them to form a Ca2+ cation, which would thus contain 20−2=18 electrons. Similarly, a phosphorus atom (Z=15) gains three electrons to form a P3− anion that contains 15+3=18 electrons.
Positively-charged protons in the nuclei attract the negatively-charged electron cloud. Each proton carries a +1 charge; the more protons an atom or ion contains the stronger the attraction it poses on its electron cloud. A nucleus of strong positive charge pulls its electron cloud towards itself tightly such that the latter would have a small radius.
The periodic table is arranged in the order of increasing proton number. Phosphorus comes the first among the five species and contains the least number of protons. Its ion would be the largest among the five. Calcium comes the last and forms the smallest ion.
Number of protons per nucleus P<S<Cl<K<CaStrength of Electrostatic attraction on the electron cloud P<S<Cl<K<CaIonic radius P3−>S2−>Cl−>K+>Ca2+
What are the characteristics of ionosphere?
Explanation:
The ionosphere is a shell of electron and electrically charged atoms and molecular that surrounds, the earth.
Trong các yếu tố sau đây: nồng độ, nhiệt độ, áp suất, diện tích tiếp xúc, chất xúc tác, có bao nhiêu yếu tố có thể ảnh hưởng tới tốc độ phản ứng?
Answer:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Explanation:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
what is the percentage composition of water in crystallization of oxalic acid
Answer:
5.17 percentage is water
Explanation:
answer from gauth math
which one of the following is not a mixture?Air,mercury ,milk,cement
mercury is not a mixture it is a element
Answer:
mercury
Explanation:
Unknown # 21
Flame Test Color: Lilac
Addition of HCl(aq)= NR (No Reaction)
Addition of HCl(aq) and BaCl2(aq)= White precipitate
Addition of HNO3(aq) and AgNO3(aq)= NR (No Reaction)
What is the unknown ionic compund molecular formula?
Which statement describes the periodic law?
Help please now!
Answer:
Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.
