Answer:
C. A down-filled coat via a p e x
Thermal insulation maintains the temperature inside the system and inhibits heat transfer. A down-filled coat would have the best thermal insulation properties. Thus, option C is correct.
What is thermal insulation?Thermal insulation is the property of the substance to resist the heat and energy transfer from a substance of abundance to a lesser concentration. They lack the conducting particles.
It inhibits the heat to get transferred to other substances. The minimum heat transfer is achieved by the structural formation and the choice of the substance.
A down-filled coat is made of insulation material that keeps warm during the winters as its structure can trap and retain heat making the person warm during colds.
Therefore, option C. A down-filled coat best shows thermal insulation.
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Which best describes the geologic time scale? (choose the best answer from below)
It explains why events happen throughout Earth’s history.
It presents the correct sequence of events in Earth’s history.
It is used to determine the absolute dates in years for different periods.
It was created by scientists who studied index fossils and climate change.
Answer: B) It presents the correct sequence of events in Earth’s history.
Explanation: edge 2021
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Answer:
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Explanation:
ggyhggggg,,,,,,,76yyygtyyhgyyggyuhu ubbububuuh7h7h
PLEASE HELP. What volume of 0.050 M of KOH neutralizes 200. mL of 0.0100 M HNO3?
a
20.0 ml
b
80.0 mL
40.0 mL
d
30.0 mL
Answer:
The answer is C. 40.0 mL.
Explanation:
To solve for the volume of KOH, start by using the formula [tex]N_{B}[/tex][tex]V_{B}[/tex] = [tex]N_{A}[/tex][tex]V_{A}[/tex] and label the information given in the question. The B in the formula stands for the base solution, and the A in the formula stands for the acid solution.
[tex]N_{B}[/tex] = 0.050 M KOH
[tex]V_{B}[/tex] = ?
[tex]N_{A}[/tex] = 0.0100 M HNO3
[tex]V_{A}[/tex] = 200. mL
Next, use the formula [tex]N_{B} V_{B} = N_{A}V_{A}[/tex], and in order to find the volume for the base solution, the formula will have to be derived for [tex]V_{B}[/tex]. The formula will now look like [tex]V_{B}= \frac{N_{A} V_{A} }{N_{B} }[/tex].
Then, plug in the information given in the question. The equation will look like [tex]V_{B}= \frac{(0.0100 M HNO_{3} {})(200. mL) }{0.050 M KOH}[/tex]. Finally, solve the equation, and the answer will be 40.0 mL.
The half-life of 42K is 12.4 hours. How much of a 750.0-gram sample is left after 62.0 hours?
Answer: 23 g
Explanation:
Amountafter = Amountbefore * (1/2)^(t/thalf)
Amountafter = (750 grams) * (1/2)^(62.0 hours/12.4 hours)
Amountafter = 23.4375 grams
750 has 2 significant digits
12.4 and 62.0 have 3 significant digits
So we take the lower of 2 significant digits:
23 grams
The half-life of 42K is 12.4 hours. 23.4375 grams of a 750 grams sample left after 62.0 hours.
What is Half Life ?Half life is the amount of time required to reduce to one-half of its initial value. The symbol of half life is [tex]t_{1/2}[/tex].
How to calculate the remaining quantity when half life given ?It is expressed as:
[tex]N(t) = N_{0} (\frac{1}{2})^{\frac{t}{t_{1/2}}[/tex]
where,
N(t) = quantity remaining
N₀ = initial quantity
t = elapsed time
[tex]t_{1/2}[/tex] = half-life of the substance
Here,
N₀ = 750.0 g
t = 62 hr
[tex]t_{1/2}[/tex] = 12.4
Now put the values in above equation we get
[tex]N(t) = N_{0} (\frac{1}{2})^{\frac{t}{t_{1/2}}[/tex]
[tex]N(t) = 750 \times (\frac{1}{2} )^{\frac{62}{12.4}}[/tex]
[tex]N(t) = 750 \times (\frac{1}{2})^5[/tex]
[tex]N(t) = 750 \times \frac{1}{32}[/tex]
N(t) = 23.4375 grams
Thus, from the above conclusion we can say that the 23.4375 grams of a 750 grams sample left after 62.0 hours.
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During which change of state would the volume of a substance increase the most?
O deposition
O melting
O vaporization
O sublimation
You have learned how to take steps that are exactly 1m long. You take 12 steps north, then 15 steps north, 35 steps south, 11 steps south, then 16 steps north. What distance have you walked? What is your total displacement?
Answer:
you have walked 69 steps but your current location is -13
Write a neutralization reaction to form the salt k2so4
H2SO4 + 2KCL ----------› K2SO4 + 2HCL
hope it helps you ♡♡
A solution contains 35.00 g of sodium chloride in 100. G of water at 45.0C. How could this solution be described
Answer:
It is unsaturated
Explanation:
A solution is said to be unsaturated when it contains less solute than it can normally hold at a given temperature.
The solubility of NaCl remains fairly independent of temperature hence the line for the solubility of NaCl remains fairly flat in the solubility curve.
The solubility of NaCl is about 36 g of NaCl in 100g of water. Hence a solution that contains 35.00 g of sodium chloride in 100 g of water at 45.0C is unsaturated.
how many moles of hydrogen ions are present in a 2L solution with a pH of 2.75
We are given:
Volume = 2 L
pH = 2.75
Finding the concentration required:
we know that pH is just the negative log of the hydrogen ion concentration
pH = -log[H⁺]
we are given that the pH is 2.75
2.75 = -log[H⁺]
log[H⁺] = -2.75 [multiplying both sides by -1]
[tex]10^{log[H]} = 10^{-2.75}[/tex]
[H⁺] = 1.78 * 10⁻³ Molar
Number of moles of Hydrogen ions:
[H⁺] = 1.78 * 10⁻³ Molar
which means that there are 1.78 * 10⁻³ moles of hydrogen ions in 1 liter solution
1.78 * 10⁻³ moles / L
multiplying and dividing by 2, we get:
3.56 * 10⁻³ moles / 2 L
Hence we need 3.56 * 10⁻³ moles of hydrogen ions
Answer:
3.556x 10^-3mol
Explanation:
Using pH =-log [ H+], we can calculate the concentration of the hydrogen Ions.
pH =-log [ H+], pH = 2.75
2.75 = -log[H+], taking antilog of both sides
10^ — 2.75 = [H+]
[H+] =1. 778 x 10^-3M
Now that we have the concentration and also knows the volume, we can use the relation
Moles = concentration X volume
= 1. 778 x 10^-3M x 2L = 3.56x 10^-3mol
The moles of the hydrogen Ions is 3.56x 10^-3mol
2. Which element below would be the best choice when creating a covalent molecule with an
Oxygen atom?
A. Na
B. Mg
C. Ne
D. O
Answer:
The chemical elements most likely to form covalent bonds are those that share electrons, such as carbon, as opposed to those that take them from another element to form an ionic bond. In general, they are nonmetals with similar electronegativities.
Explanation:
Answer:a
Explanation:
need help asap electrons
positively charged, subatomic particles found in the nucleus of the atom
2. metals
elements with properties intermediate between those of metals and nonmetals
3. period
a homogeneous mixture whose particles are too small to reflect or scatter light
4. compound
two or more elements that have chemically combined
5. solution
elements that are malleable, polish to a luster, conduct heat and electricity well and tend to lose electrons in a chemical reaction
6. protons
a vertical column on the periodic table
7. group
a horizontal row on the periodic table
8. metalloids
negatively charged, subatomic particles
Answer:
need help asap electrons
positively charged, subatomic particles found in the nucleus of the atom
2. metals
elements with properties intermediate between those of metals and nonmetals
3. period
a homogeneous mixture whose particles are too small to reflect or scatter light
4. compound
two or more elements that have chemically combined
5. solution
elements that are malleable, polish to a luster, conduct heat and electricity well and tend to lose electrons in a chemical reaction
6. protons
a vertical column on the periodic table
7. group
a horizontal row on the periodic table
8. metalloids
negatively charged, subatomic particles
Explanation:
A déliquescent salt of a divalent metal
Answer:
CaCl2
Explanation:
how many molecules are in 3cacl2
Answer:
The molar mass and molecular weight of 3CaCl2 is 332.952.
Which of the following reactions is balanced?
A)
Sn2+ + 2Fe3+ → Sn4+ + 2Fe2+
B)
Sn2+ + 2Fe3+ → Sn4+ + Fe2+
C)
Sn2+ + Fe3+ → Sn4+ + Fe2+
D)
2Sn2+ + Fe3+ → 2Sn4+ + Fe2+
Answer:
A
Sn2+ + 2Fe3+ > Sn4+ + Fe2+
Pls answer ill give brainliest question in pic
C is the correct answer
Temperature increases as you gain altitude in the stratosphere and the thermosphere. Temperature increases in altitude within the stratosphere because of the ozone layer.
—————
Please remember to revise this and make it in your own words if you want! I hope this helps you. -Doodle
—————
In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 200 grams and mass was decreasing by 11% per day. Determine the mass of the radioactive sample at the beginning of the 10th day of the experiment. Round to the nearest tenth (if necessary).
Answer:
The correct answer is - 62.36 g.
Explanation:
Given:
Mass of substance - 200
decreasing rate - 11% per day
mass at the beginning of the 10th day - ?
Solution:
F(x) = 200*(1 - 11)^x
here x the time
F(x) = 200* (0.89)^10
= 200*0.3118
= 62.3634
Thus, the correct answer is 62.36 g.
what is a reaction that uses a catalyst?
One of the most commonly known catalysed reaction is that of Hydrogen Peroxide turning into Water
In this reaction, we can use Potassium Permanganate (KMnO₄) or Palladium (Pd) as a catalyst.
These catalysts helps Hydrogen Peroxide turn into water and oxygen
Catalyst: Substances that change the rate of a chemical reaction and themselves remain chemically unchanged after the reaction are called catalysts.
Example:- In the process of manufacturing of ammonia Fe is used as Catalyst.
[tex]N _{2} (g)+ 3H _{2} (g) \huge \rightarrow {}^{Fe}\rightarrow \small{3NH _{3}(g)}[/tex]
Note:- there is only one arrow. I was unable to put iron over the arrow ..
Hope This Helps You ❤️The energy of motion is called kinetic energy ? True or false
Answer:
True
Explanation:
Trust me
Answer:
True. Kinetic energy is the energy of motion. All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward.
Carbon monoxide has _____of oxygen.
One atom
Zero atoms
Two atoms
30 ml of gas is changed from 4 atm to 2 atm what is the new volume
Answer:
[tex]\boxed {\boxed {\sf 60 \ mL}}[/tex]
Explanation:
In this problem, volume and pressure are changing, so we use Boyle's Law. This states that the volume of a gas is inversely proportional to the pressure. The formula for this law is:
[tex]P_1V_1=P_2V_2[/tex]
Originally the gas has a volume of 30 milliliters and a pressure of 4 atmospheres.
[tex]4 \ atm * 30 \ mL=P_2V_2[/tex]
The pressure is changed to 2 atmospheres, but the new volume is unknown.
[tex]4 \ atm * 30 \ mL = 2 \ atm *V_2[/tex]
We want to solve for the new volume (V₂). It is being multiplied by 2 atmopsheres. The inverse operation of multiplication is division, so we divide both sides by 2 atm.
[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= \frac{ 2 \ atm *V_2}{2 \ atm}[/tex]
[tex]\frac{4 \ atm * 30 \ mL}{ 2 \ atm}= V_2[/tex]
The units of atmospheres (atm) cancel.
[tex]\frac{4 * 30 \ mL}{ 2 }= V_2[/tex]
[tex]\frac{120 \ mL}{2}= V_2[/tex]
[tex]60 \ mL= V_2[/tex]
The new volume of the gas is 60 milliliters.
i need helpppppppp!!!!!
Answer:
Sorry I want to help but I dont know the answer
Calculate the number of atoms in 13.2 mole copper
In the given question, [tex]7.949 \times 10^{24}[/tex] atoms are present in 13.2 mole of copper.
A mole is defined as the amount of a substance that contains exactly [tex]6.022\times 10^{23}[/tex] 'elementary entities' of the given substance.
The number of atoms in 13.2 moles of copper (Cu) can be calculated using Avogadro's number.
To calculate the number of atoms in 13.2 moles of copper, we can multiply the number of moles by Avogadro's number:
Number of atoms = [tex]\rm 13.2\ moles\ \times[/tex] [tex]6.022\times 10^{23}[/tex] atoms/mole
Number of atoms = [tex]7.949 \times 10^{24}[/tex] atoms
Therefore, in 13.2 moles of copper, there are approximately [tex]7.949 \times 10^{24}[/tex] atoms.
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The Sun has six regions or layers. Identify the Sun's layers, beginning with the innermost and moving out.
1. Innermost
convective zone
2. 2nd innermost
corona
3. 3rd innermost
core
4. 4th innermost
photosphere
5. 5th innermost
chromosphere
6. Outermost
radiative zone
Answer:
Beginning from the innermost layer and moving towards the outermost of the sun that has six layers.
1. Innermost layer is the core: All the energy of the sun comes from core. Here hydrogen and helium are components that are present.
2. Radiative zone: The high-energy photons are move from the innermost core to the second innermost radiative zone.
3. Convective zone: It is a comparatively cooler layer to the core and radiative zone.
4. Photosphere: It is the 4th innermost region with sunspots and called the magnetic field of the sun.
5. Chromosphere: This red color layer with filaments of gas is cooler than the photosphere.
6. Corona: It is the outermost layer of the sun and the temperature is much higher here.
PLEASE HELP!
mass number - atomic number =
Answer:
Number of neutrons
Explanation:
The mass number represents the number of protons and neutrons combined and the atomic number only represents the number of protons.
mass number - atomic number = number of neutrons
Answer:
mass number - atomic number = number of neutrons
Explanation:
The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. The mass number minus the atomic number represent the number of neutrons.
If the half-life of substance Z is 2.5 years, how long would it
take for 48 grams of substance Z to decay such that only 3
grams remain?
It takes 10 years for the substance z to decay from 48g to 3g
Half life of z = 2.5 years
Final amount of Z = 3 g
Initial amount of Z = 48 g
According to the question, it takes 2.5 years for substance Z to reduce to half.
So,
In 2.5 years, the amount of z = 48/2 = 24 grams
In next 2.5 years, the amount of z = 24/2=12g
In next 2.5 years, the amount of z = 12/2=6g
In next 2.5 years, the amount of z = 6/2=3g
To reduce the amount from 48g to 3g, total years = 2.5 + 2.5 + 2.5 + 2.5
= 10 years
Therefore, it takes 10 years for the substance z to decay from 48g to 3g
The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the emperical formula.
Answer:
D)subscript of C in molecular formula = n x subscript of C in empirical formula
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
.The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the empirical formula? a)<br /><br /> empirical formula mass / molecular mass = n<br /><br /> B) molecular mass = element mass / empirical formula mass ´ 100<br /><br /> c) subscript of H in empirical formula = 2  subscript of H in molecular formula<br /><br /> D) subscript of C in molecular formula = n  subscript of C in empirical formula<br /><br />
An empirical formula can be regarded as "shorten form" of a molecular formula. Instance of this is
A compounds CH4, C2H8, C4H12... with empirical formula of CH4. In this case a constant "n" represent the difference that exist between empirical formula and molecular formula, "n" which is a whole number, molecular formula is the numerator.
Therefore, subscript of C in molecular formula = n x subscript of C in empirical formula
If you sprain your ankle and place a cold pack on it, how does the motion of molecules in your ankle change?
Answer:
that heat energy speeds up the motion of the particles and the temperature of the reaction
Explanation:
HOPE IT HELPS
When we place an ice pack on a sprained ankle, the blood flow is reduced which prevents further swelling, ice reduces the blood flow which is necessary when the ankle is injured.
What happens after placing an ice pack?The flow of blood and the lymph vessel is limited or decreased after applying an ice pack, this is an immediate first aid to be given to the injured person
After 2-3 days of the injury, a hot pack should be applied to increase the blood flow and the lymph flow for an activity.
Hence, the molecule flow is reduced after applying an ice pack to the sprained ankle
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Name the fundamental unit involved in the derived unit joule?
Answer:
Energy
Explanation:
If Beryllium were to lose a proton, it would become a(n)
Answer:
an anion
Explanation:
since it lost a proton..it now has 3 protons and four electrons and possesses a minus charge since it is no longer neutrally charged..this minus charge makes it an anion
How many grams of manganese (III) iodide (Mn13) will be needed to make 1.3 grams of hydrogen iodide (HI)? g MnI3
Answer:
I dont know
Explanation:
I need it to