Answer:
Physical change
Explanation:
Because it doesn't require any chemical to change
Answer:
Physical change
Physical change
Physical change
Physical change
Explanation:
dentify the missing information for each atom or ion. Note that the atoms and ions are not necessarily neutral. A Se ion has a mass number of 78 and a charge of −2 . Determine the number of neutrons, protons, and electrons in this ion. number of neutrons: 44 number of protons: 34 number of electrons: 36 An ion has a mass number of 65, 36 neutrons, and a charge of +1 . Identify the element symbol, and determine the number of protons and electrons in this ion. element symbol: Cu number of protons: 30 number of electrons: 29 An atom or ion has 43 neutrons , 36 protons, and 36 electrons. Identify the element symbol, and determine the mass number and charge for this atom or ion. element symbol: Au mass number: 79 charge: 0
Answer:
Check the explanation
Explanation:
1)
Atomic number of Se = 34
So, number of proton = 34
use:
charge = number of proton - number of electron
-2 = 34 - number of electron
number of electron = 36
number of neutron = mass number - atomic number
= 78 - 34
= 44
Answer:
44
34
36
2)
number of proton = mass number - number of neutron
= 65 - 36
= 29
29 is atomic number for Cu
use:
charge = number of proton - number of electron
+1 = 29 - number of electron
number of electron = 28
Answer:
Cu
29
28
3)
Atomic number is 36 for Kr
use:
charge = number of proton - number of electron
= 36 - 36
= 0
use:
mass number = number of proton + number of neutron
= 36 + 42
= 78
Answer:
Kr
78
0
When Mrs. Green describes the physical properties of matter she said that physical properties often concern changes in state, One
physical property that does not describe a change in state is
A)
density
B)
evaporation
C)
freezing
D)
melting
Answer:
density
Explanation:
Density is an important measurement. It has an unit: g/mL or kg/L, ...
Evaporation, freezing, melting are the processes in which the substances change their states. Other processes are: condensation, sublimation, deposition.
...
Hope this answer can help you. Have a nice day!
What are the three components of the cell theory?
Answer:
IN the description
Explanation:
The generally accepted parts of modern cell theory include:
All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms.
Answer:
Sample Response: The first component of the cell theory says that all living things are made of cells. The second component of the cell theory states that cells are the basic structure and function of living things. The last component of the cell theory says that cells come from other cells.
What is another term for anode?
Answer:positive electrode
Explanation:
Anode can also be referred to as positive electrode in a cell
6. Bacteriorhodopsin is an integral membrane protein that uses solar energy (absorbed by its retinal chromophore) to pump protons out of the cell against an electrochemical gradient. Re-entry of the protons into the cell (down the gradient through its ATPase) is then used to drive the synthesis of ATP from ADP and Pi. Consider the following conditions: intracellular pH is 9.4 and extracellular pH is 6.4, and there is a transmembrane electrical gradient of 120 mV (negative inside). The concentration of intracellular [ATP] = 1 mM, [ADP] = 50 µM, and [Pi] = 2 mM, and G° for ATP hydrolysis is -30.5 kJ/mol. Temperature is 27 °C. a. What is the energy cost of pumping one mole of H+ out of the cell? b. What is the minimal number of H+ that must re-enter the cell through the ATPase to provide sufficient energy to synthesize each ATP? Explain how you arrived at this answer quantitatively, of course.
Answer:
Explanation:
Hello!
a)
You have an integral membrane protein (Bacteriorhodopsin) that uses solar energy to pump protons out of the cell against its electrochemical gradient.
To calculate the energy needed by the protein to pump one molecule out of the cell you need to apply the free energy difference equation for a charged molecule:
ΔG= 2.303RTlog₁₀[tex](\frac{[H^+]out}{[H^+]in})[/tex]+zFΔV
Where
ΔG= free energy difference per molecule transferred from the inside to the outside
R= gas constant 8.315*10⁻³ kJ/mol
T= Temperature in Kelvin (273.15 + TºC)
z= Valency of the ion (ej Na⁺ is z= +1 and Cl⁻ is z= -1)
F= Faraday constant 96.5 kJ/V*mol
ΔV= membrane potential (Volts)
The information you have is:
Intracellular pH= 9.4
Extracellular pH= 6.4
ΔV= 120 mV
Temperature 27ºC
Using the values of pH you can calculate the intracellular and extracellular proton concentrations:
Remember the pH of a solution is calculated as pH=-log[H⁺] so if you reverse the logarithm, you'll find the concentration of protons:
b= logₐ C ⇒ C= aᵇ
[H⁺]intracelular= 10⁻⁹'⁴
[H⁺]extracelular= 10⁻⁶'⁴
Now you need to match the units of the temperature and electrical gradient to the ones in the equation:
The temperature needs to ve in Kelvin: T= 273.15 + 27ºC= 300.15K
The electrical gradients need to be in Volts: ΔV= 120 mV= 0.12V
Now you can replace the data in the formula and calculate how much energy is needed to pump one proton outside the cell:
ΔG= 2.303RTlog₁₀[tex](\frac{[H^+]out}{[H^+]in})[/tex]+zFΔV= 2.303*( 8.315*10⁻³ kJ/mol)*300.15K*log[tex](\frac{10^{-6.4}}{ 10^{-9.4}} )[/tex]+(+1)*96.5 kJ/V*mol*0.12V= 28.82 kJ/mol
It costs 28.82 kJ/mol to pump one mole of H⁺ outside the cell.
b)
To synthesize one molecule of ATP the ATP synthase uses the electrical gradient produced by the spontaneous pass of protons through the membrane. This process is called the proton-motive force.
The ATP synthase consists of two subunits F₀ and F₁ with a rotational motor mechanism that allows it to produce and release ATP.
F₁ has the subunits α, β, σ, γ, ε in charge of synthesizing ATP
F₀ is a proton pore, made of 3 subunits a, b and c. 6 subunits c make up the transmembrane ring in charge of rotation, this ring is connected to the subunits γ and ε. Each time a proton passes, it makes the ring rotate which makes the subunits γ rotate.
Each time the subunit γ rotates 360º, 3 ATP molecules are synthesized and freed. A full rotation of γ means that the c-ring also made a full rotation (for this you need one proton per subunit)
If the ring has 6 c-subunits and, then each ATP molecule needs 6/3= 2 protons to need to pass for each ATP molecule.
I hope this helps!
Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because A.the bromine radical is more reactive and therefore more selective. B.the chlorine radical is more reactive and therefore more selective. C.the chlorine radical is less reactive and therefore more selective. D.the bromine radical is less reactive and therefore more selective. E.none of these choices.
Answer:Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because the bromine radical is less reactive and therefore more selective.
Explanation: Halogenation occurs when a halogen replaces one or more hydrogen atoms in an organic compound ie chlorine or bromine with the reactivity of the halogens decreasing in the order of F2 > Cl2 > Br2 > I2
Since fluorine reacts explosively making it is difficult to control, and iodine is unreactive. Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine with Chlorination ie chlorine radical being more reactive and not selective and the Bromination of alkanes ie bromine radical occurring similarly but slower and less reactive but more selective which is due to the fact that a bromine atom is less reactive in the hydrogen abstraction than a chlorine atom evidence in the higher bond energy of H-Cl than H-Br.
To make a is to settle a disagreement by giving up some personal demands
Answer:
Compromise
Explanation:
Please give brainliest :-)
Answer:
Compromise
Explanation:
the perimeter of a isosceles is 48 meters. the upper base is 12 meters shorter than the lower base x.each leg is 12 meters shorter than the lower base x. each leg is 12 meters shorter than the lower base. write the equation of the perimeter in terms of x.
[HCN]=0.09974 M
Kp=7.52
Calculate the partial pressure of HCN ?
Answer:
i don't understand
Explanation:
Please help! BRANLIEST to right answer
Answer:
Endothermic, positive
Explanation:
Which energy source is a nonrenewable resource?
Answer:
Fossil fuels.
Explanation:
Non-renewable energy comes from sources that will run out or will not be replenished in our lifetimes—or even in many, many lifetimes. Most non-renewable energy sources are fossil fuels: coal, petroleum, and natural gas. Carbon is the main element in fossil fuels.
Answer:
Fossil fuel
Explanation:
I searched this up since I forgot.
How many grams do 4.8 x 1026 atoms of silicon
weigh?
Answer in units of g.
What is the relationship between the degree of ionization and conductivity?
A. The lower the degree of ionization, the stronger the conductivity.
B. The higher the degree of ionization, the stronger the conductivity.
C. Conductivity is directly proportional to the degree of ionization.
D. Conductivity is inversely proportional to the degree of ionization.
Answer:
B
Explanation:
What should happen if a good experiment is replicated?
The results will decrease.
The results will increase.
The results will be different.
The results will be similar.
Answer:
The results will be similar.
The alcohol functional group is composed of elements
Answer:carbon, hydrogen and oxygen
Explanation:
Alcohol functional group is composed of carbon, hydrogen and oxygen
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
*Text me at 561-400-5105 for private tutoring if interested: I can do homework, labs, and other assignments :)
234.
In the equation:
Th →
90
particle is presented by.X?
234
Pa + X, which
91
0
1
1.
3.
-70
TH
0
4
He
2.
4.
*70
Answer:
the answer woul be 89 if you do the math right
Explanation:
Why is scientist Robert Hazen using pressure bombs to blow up minerals
Answer:
Hazen uses small metal cylinders called pressure bombs to blast minerals with insanely high pressures and temperatures. He's using that knowledge to figure out how ancient minerals might have been involved in the evolution of the first primitive life-forms.
Explanation:
Nikolas, the fire extinguisher, and the skateboard have a combined mass of 50 kg. What force would the fire extinguisher have to produce to propel nikolas if he wanted to accelerate at a rate of 1.2 m/s squared
Answer:
Force used by fire extinguisher = 60 N
Explanation:
Given:
Mass of skateboard with fire extinguisher = 50 kg
Acceleration of fire extinguisher = 1.2 m/s²
Find:
Force used by fire extinguisher = ?
Computation:
⇒ Force = Mass × Acceleration
⇒ Force used by fire extinguisher = Mass of skateboard with fire extinguisher × Acceleration of fire extinguisher
⇒ Force used by fire extinguisher = 50 kg × 1.2 m/s²
⇒ Force used by fire extinguisher = 60 N
Answer:
Force=60 N
Hope this helps ya'll!
The percent yield of a reaction in which 52 grams of a reactant is expected to yield 30 grams of product is 25%. What is the actual yield of the reaction? A) 13 grams B) 120 grams C) 208 grams D) 7.5 grams
Answer:
D) 7.5 grams
Explanation:
Hello,
In this case, since the percent yield is defined by:
[tex]Y=\frac{m^{actual}}{m^{theoretical}} *100\%[/tex]
In such a way, since the percent yield is up to 25% and the expected or theoretical amount is 30 g of the product, the actual yield of the reaction is:
[tex]m^{actual}=\frac{Y*m^{theoretical}}{100\%} =\frac{25\%*30g}{100\%} \\\\m^{actual}=7.5g[/tex]
Therefore the answer is D) 7.5 grams.
Best regards.
At constant temperature and moles, what happens to the pressure of a gas
as the volume of that gas increases? *
Answer:
Avagadro's Law- Gives the relationship between volume and amount of gas in moles when pressure and temperature are held constant. If the amount of gas in a container is increased, the volume increases. ... This means more impacts on the walls of the container and an increase in the pressure.
Explanation:
Prepare a flow diagram for extraction of 2-chlorobenzoic acid and 1,4-dichlorobenzene.
Answer:
See explanation below
Explanation:
To do aflow diagram for extraction of these two components of a sample, we need to analize both reagents so we can make a great diagram and separate both reagents.
First, let's see the acid. The 2-chlorobenzoic acid is a relativel strong acid, so, in order to separate this from a sample we need to use a base to do so. However, it's very important the use of the base here, we cannot use any base to do it, for the main reason that the sample has other component, and this component may react too with the base and the separation will not be succesfull. So, as the chlorobenzoic acid is a relatively strong acid, if we use a strong base such as NaOH, this will react with the acid, but it will also react with the 1,4-dichlorobenzene forming a Sn2 product and a salt like this.
C₆H₄Cl₂ + NaOH ---------> C₆H₅OCl + NaCl
This is the reason which we cannot use NaOH, because it's a strong base that may react with other compounds in the sample.
To solve this, we can use a weak base such as NaHCO₃. This weak base has the strength enough to react with the benzoic acid, but not strong enough to react with the dichlorobenzene.
So, the first step is dissolve the sample in an organic solvent like ether. The next step is mixing the sample with NaHCO₃. This will cause the layer to divide into two layers. One aqueous layer that will have the product of the acid with the base, and an organic layer with the dichlobenzene. Afterward, we just need to use a strong acid like HCl, but dilluted in the aqueous layer to regenerate the acid, and in the organic layer, just heat the solution til the whole solvent evaporates completely.
The flow diagram is below in the attached picture.
Question 17 In the Haber reaction, patented by German chemist Fritz Haber in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. This reaction is now the first step taken to make most of the world's fertilizer. Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that 786. liters per second of dinitrogen are consumed when the reaction is run at 222.°C and 0.35atm. Calculate the rate at which ammonia is being produced. Give your answer in kilograms per second. Round your answer to 2 significant digits.
Answer:
Explanation:
N₂ + 3H₂ = 2 NH₃
1 vol 2 vol
786 liters 1572 liters
786 liters of dinitrogen will result in the production of 1572 liters of ammonia
volume of ammonia V₁ = 1572 liters
temperature T₁ = 222 + 273 = 495 K
pressure = .35 atm
We shall find this volume at NTP
volume V₂ = ?
pressure = 1 atm
temperature T₂ = 273
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
[tex]\frac{.35\times 1572}{495} =\frac{1\times V_2}{ 273 }[/tex]
[tex]V_2 =303.44[/tex] liter .
mol weight of ammonia = 17
At NTP mass of 22.4 liter of ammonia will have mass of 17 gm
mass of 303.44 liter of ammonia will be equal to (303.44 x 17) / 22.4 gm
= 230.28 gm
=.23 kg / sec .
Rate of production of ammonia = .23 kg /s .
What will happen if ultraviolet light shines on metal
Answer:
if this doesnt help then im sorry...
Explanation:
When light is shined on certain metals, electrons may be knocked off the metal. This is called the photoelectric effect. By assuming that light is quantized, Einstein was able to explain the photoelectric effect. ... When UV light of a long wavelength and low frequency is shined on the zinc nothing happens.
Ah yay! Something I can answer.
Answer:
When UV light is shined upon certain metals something called the photoelectric effect occurs. The photoelectic effect is when electrons are discharged from the metal.
Explanation:
Metals contain many electrons and when the electrons are given enough energy they can leave the metal. The electrons that escape the metal are called photoelectrons; hence why this effect is called the photoelectic effect.
Metamorphic rocks directly form from
Answer:
Metamorphic rocks are formed from pre-existing rock and sediment materials. They are formed when igneous, sedimentary, or other pre-existing metamorphic rocks are exposed to the heat and pressure as well as super-heated mineral-rich fluids. They are compacted together to form a new rock altogether. Metamorphism does not include the melting or liquefaction of the pre-existing rock. Instead, it compacts them and crushes them, pushing them together at extreme heat and pressure to form a new rock altogether composed of sedimentary, igneous, and other metamorphic rock. It's the rock hybrid of the geologic world.
Metamorphism is similar to when you squish playdough together, it doesn't form a new playdough color (unless you REALLY mixed that poor playdough together). It forms an amalgamation of different colors and patterns made from the other rock.
Taken from a paper I once wrote I explained this again:
"Metamorphic rocks are formed when pre-existing rocks and their minerals are compressed and altered by Earth’s internal processes; interior pressure, temperature (heat), and chemical reactions. The minerals and pre-existing rock necessary for the creation of metamorphic rock must then also be located deep underground if such processes are expected to make an impact and create a metamorphic rock."
What is the molality of a solution that contains 31.0 g HCl in 5.00 kg water? (molar mass of
HCI = 36.46 g/mol)
Answer:
0.17M
Explanation:
5kg of water contains 5 liters as the density of water is 1000 [tex]kgm^{-3}[/tex]
Therefore one liter of water contains 31/5=6.2g of HCl
Molality of the solution = 6.2/36.46 =0.17M
Which factor would slow down a chemical reaction? (Choose all that apply)
A)Adding an inhibitor
B)Decreasing temperature
C)Decreasing particle size
D)Increasing particle size
Answer:
(decreasing particle size) C
Explanation: That is one of the answers, if there are more I am sorry.
The rate of the reaction is ?
The rate of a chemical reaction is defined as the change in the concentration of a reactant or a product over the change in time, and concentration is in moles per liter, or molar, and time is in seconds. So we express the rate of a chemical reaction in molar per second.
Answer:
Hey!
Your answer is The Rate of a Reaction is a measurement of how the speed at which a reactant is used up / or a product is formed.
Explanation:
R of R (Rate of Reaction) can be affected by:
Reactant concentration (how much of the substance is there to react)
The state of the reactants (whether they are in a solid/liquid/gas state)
The total surface area (more particles of the substance means more reactions...)
The Temperature (hot=quicker cool=slower)
The presence of a catalyst (catalysts speed up the Rate of the Reaction)
HOPE THIS HELPS!!
If you collect 1.75 L of hydrogen gas during a lab experiment, when the room temperature is 23ºC and the barometric pressure is 105 kPa, how many moles of hydrogen will you have?
Answer:
[tex]n=0.0747mol[/tex]
Explanation:
Hello,
In this case, since we can consider hydrogen gas as an ideal gas, we check the volume-pressure-temperature-mole relationship by using the ideal gas equation:
[tex]PV=nRT[/tex]
Whereas we are asked to compute the moles given the temperature in Kelvins, thr pressure in atm and volume in L as shown below:
[tex]n=\frac{105kPa*\frac{0.009869atm}{1kPa}*1.75L}{0.082\frac{atm*L}{mol*K}*(23+273.15)K} \\\\n=0.0747mol[/tex]
Best regards.
2. What happens to the pH when you add more H+ ions to a solution that has no buffers?
