Answer: It's gravity keeps the Moon orbiting around the Earth.
Explanation:
The nuclear fission of U-235 can occur by different pathways. If 1 neutron is absorbed by U-235 to produce 36 neutrons and Kr-94, identify other nucleus that is produced using the boxes and pull-down menu provided. g
Answer:
See explanation
Explanation:
What I have written in the image attached is called a nuclear equation. It differs from a chemical reaction equation in the sense that it involves transformations that occur in the nucleus of atoms.
The nuclear equation must be balanced. This means that the mass and charge on both sides of the reaction equation must be the same.
On the left hand side the U-235 interacts with a neutron. The total mass on the left hand side is 236 while the total charge is 92. If we sum up the masses and charges of Ba and Kr, we also get a total of 236 mass units and a charge of 92.
Hence the other nucleus is barium-141
How much acceleration does a 10 kg object have if pushed by a 75 N force?
a = 7.5 m/s²
Explanation:Hi there !
Newton's second law
F = m×a => a = F/m
1 N = 1kg·m/s²
a = (75kg.m/s²)/10kg
= 7.5 m/s²
Good luck !
Why is this dietary supplement best characterized as a mixture instead of a pure substance?
A. The percent daily value is less than 100 percent
B. Calcium citrate is composed of nonmetallic elements
C. A tablet contains different chemical compounds
D. Calcium citrate contains more than one element.
Answer:
C. A tablet contains different chemical compounds
Explanation:
The dietary supplement in this question depicts a kind of matter. Matter, in chemistry, can either be a pure substance or a mixture. Unlike elements and compounds (pure substances) which cannot be separated by physical means, mixtures can be separated using physical method.
A mixture is a combination of different substances with varying physical properties, which serves as basis of their physical separation. According to the image in the question, the Calcium citrate dietary supplement contains different chemical compounds like polyethylene glycol, sodium, methyl cellulose, magnesium silicate etc.
These chemical compounds retain their individual properties and can be separated easily via physical techniques, hence, the dietary supplement is a MIXTURE.
Show the net dipole moment (μ = 0 D) of the compounds
a) CBr4
b) cis-1,2-Dibromoethene
c) trans:-1,2-Dibromoethene
d) 1,1-Dibromoethene
Answer:
A
Explanation:
Using the equation above, the dipole moment is calculated to be 1.85 D by multiplying the distance between the oxygen and hydrogen atoms by the charge difference between them and then finding the components of each that point in the direction of the net dipole moment (the angle of the molecule is 104.5˚).
Which of the following best describes the structure of a protein?
a
Carbon ring(s)
b
Hydrocarbon(s)
c
Single or double helix
d
Globular or fibrous
Answer:
I'm pretty sure its d.
Explanation:
because a gbular protein is a protein that is round in shape, and a fibrous is a long a thin shaped protein. Which those are two kinds of proteins.
A bicycle rider is applying a force of 20 N while heading south against a wind blowing from the south with a force of 5 N
Answer:
the bike will go down 5 N
Need help with 8 plssss
Answer:
c,a,b,d
Explanation:
Which of the following is an example of physical change?
Answer: The glass cup falling
Explanation:
It didnt change chemically, only its physical appearance
A solution in which the pH is 1.6 would be described as
a.
very acidic
b.
slightly acidic
c.
very basic
d.
slightly basic
e.
neutral
Answer:
a. very acidic
Explanation:
A solution with a pH of 1.6 would be described as a very acidic solution.
The pH scale is a convenient scale for expressing the level of acidity or alkalinity of aqueous solutions.
The scale ranges from 1 to 14 in which case 1 is the lower limit and 14 the upper limit.
An acidic solution has a pH value less than 7. As pH decreases, the acidity of the solution increases. Neutral solutions have a pH of 7An alkaline solution has a pH greater than 7 and the level of alkalinity increases as pH increases.Consider the reactionI2(g) + Cl2(g)2ICl(g)Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 2.41 moles of I2(g) react at standard conditions.S°surroundings = J/K
We know,
[tex]\Delta H_{I_2(g)}=62.438\ KJ/mol\\\\\Delta H_{Cl_2(g)}= 0.0\ KJ/mol\\\\\Delta H_{ICl(g)}=17.78\ KJ/mol[/tex]
For given reaction, [tex]I_2(g)+Cl_2(g)\ -->\ 2ICl(g)[/tex]
[tex]\Delta H_{rxn}=2\Delta H_{ICl(g)}-\Delta H_{I_2(g)}-\Delta H_{Cl_2(g)}\\\\\Delta H_{rxn}=2(17.78)-0-62.438\ KJ/mol\\\\\Delta H_{rxn}=-26.878\ KJ/mol[/tex]
For , 2.41 moles of [tex]I_2[/tex] :
[tex]\Delta H_{rxn}=2.41\times (-26.878)\ KJ\\\\\Delta H_{rxn}=-64.78\ KJ[/tex]
We know :
[tex]\Delta S = -\dfrac{\Delta H_{rxn}}{T}\\\\\Delta S = -\dfrac{-64.78}{298}\ KJ/K\\\\\Delta S =-0.21738 \ KJ/K\\\\\Delta S=-217.38\ J/K[/tex]
Hence, this is the required solution.
PLS HELP WILL DO BRAINLIEST! PLS PLS PLS PLS PLS HELP ASAP Atoms of two different elements must have different
electrical charges.
numbers of neutrons.
atomic numbers.
energy levels.
the answer is atomic numbers
Answer:
atomic numbers
Explanation:
In order for two atoms to be different, they have to have a different number of protons. Protons are represented by the atomic number. Thus, atoms of two DIFFERENT elements must have different atomic numbers.
I took the test and got 100%
Hope this helps!
An analytical chemist weighs out 0.055g of an unknown triprotic acid into a 250mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.1300M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 6.6mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits.
Answer:
Mass of the unknown acid is 4.0g
Explanation:
The determine the molar mass of the unknown acid, the steps below can be followed
Firstly, determine the concentration of the acid, the formula below can be used;
ConcA × Va/ConcB × Vb = Na/Nb
Where ConcA is the concentration of the unknown acid
ConcB is the concentration of the NaOH base
Va is the volume of acid and Vb is the volume of base
Since, the titration was said to have reached an equivalent point, it means the number of moles of the acid (Na) was equal to the number of moles of the base (Nb) and thus both will be assumed to be 1
Thus
ConcA × 250/0.13 × 6.6 = 1/1
ConcA = 0.13 × 6.6/250
ConcA = 0.003432M
Then, determine the actual number of moles (n) of the unknown acid used,
ConcA = no of moles of acid/volume of acid (in dm³ or L)
To convert mL to L, we divide by 1000
Hence, 250ml = 0.25L
0.003432 = n/0.25
n = 0.003432 × 0.25
n = 0.01373 moles
To determine the molar mass;
n = mass/molar mass
The mass was given in the question to be 0.055g
Thus
0.01373 = 0.055/molar mass
molar mass = 0.055/0.01373
molar mass = 4.0g
Bromine is found above iodine in Group 17 of the periodic table. If an ion formed by bromine has a charge of 1-, what is the charge on an ion
formed by iodine?
A. -7
B. -2
C. -1
D. +1
Answer:
Explanation:
Iodine is the most flexible of the atoms in Group 17 of the periodic table. It can have more than 1 charge, especially when combined with oxygen. The answer that you are expected to give, I think is C. Iodine's dominant charge is - 1
During the analysis, 0.00905 mol H2O is formed. Calculate the amount (mol) H in 0.00905 mol H2O.
Answer:
0.0181 mol H
Explanation:
Step 1: Given data
Moles of water (H₂O) formed during the analysis: 0.00905 mol H₂O
Step 2: Calculate the amount (mol) H in 0.00905 mol H₂O
According to the chemical formula of water, the molar ratio of water to hydrogen is 1:2, that is, there are 2 moles of H per 1 mole of H₂O. We will use this conversion factor to calculate the moles of H in 0.00905 moles of H₂O.
0.00905 mol H₂O × (2 mol H/1 mol H₂O) = 0.0181 mol H
The current disintegration rate for carbon-14 is 14.0 Bq. A sample of wood discovered in an archaeological excavation is found to have a carbon-14 decay rate of 0.875 Bq. If the half-life of carbon-14 is 5,700 y, approximately how old is the wood sample?
Answer:
The wood sample has an age of approximately 22800 years.
Explanation:
The Becquerel ([tex]Bq[/tex]) is a SI unit which describes radioactive activity related to decay of radioactive isotopes, which is equivalent to [tex]\frac{1}{s}[/tex]. The decay of radioactive isotope is described by the following ordinary differential equation:
[tex]\frac{dN}{dt} = -\frac{N}{\tau}[/tex] (Eq. 1)
Where:
[tex]\frac{dN}{dt}[/tex] - Disintegration rate, measured in [tex]\frac{1}{s}[/tex].
[tex]N[/tex] - Amount of remaining radioactive nuclei, dimensionless.
[tex]\tau[/tex] - Time constant, measured in seconds.
By integration the solution of this differential equation is obtained:
[tex]\int {\frac{dN}{N} } = -\frac{t}{\tau}\int dt[/tex]
[tex]\ln N = -\frac{t}{\tau} + C[/tex]
[tex]N(t) = N_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)
Let [tex]N_{1}[/tex] and [tex]N_{2}[/tex] different disintegration rates for Carbon-14 samples, so that:
[tex]N_{1} = N_{o} \cdot e^{-\frac{t_{1}}{\tau} }[/tex] (Eq. 3)
[tex]N_{2} = N_{o}\cdot e^{-\frac{t_{2}}{\tau} }[/tex] (Eq. 4)
If we divide (Eq. 4) by (Eq. 3), then:
[tex]\frac{N_{2}}{N_{1}} = \frac{N_{o}\cdot e^{-\frac{t_{2}}{\tau} }}{N_{o}\cdot e^{-\frac{t_{1}}{\tau} }}[/tex]
[tex]\frac{N_{2}}{N_{1}} = e^{-\frac{1}{\tau}\cdot (t_{2}-t_{1}) }[/tex] (Eq. 5)
If [tex]\Delta t = t_{2}-t_{1}[/tex], we proceed to clear that variable:
[tex]\ln \frac{N_{2}}{N_{1}} = -\frac{1}{\tau}\cdot \Delta t[/tex]
[tex]\Delta t = -\tau\cdot \ln \frac{N_{2}}{N_{1}}[/tex] (Eq. 6)
Time constant is also a function of half-life ([tex]t_{1/2}[/tex]), measured in seconds:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex]
If [tex]t_{1/2} = 1.798\times 10^{11}\,s[/tex], [tex]N_{1} = 14\,\frac{1}{s}[/tex] and [tex]N_{2} = 0.875\,\frac{1}{s}[/tex], the age of the wood sample is:
[tex]\tau = \frac{1.798\times 10^{11}\,s}{\ln 2}[/tex]
[tex]\tau = 2.594\times 10^{11}\,s[/tex]
[tex]\Delta t = -(2.594\times 10^{11}\,s)\cdot \ln \left(\frac{0.875\,\frac{1}{s} }{14\,\frac{1}{s} } \right)[/tex]
[tex]\Delta t \approx 7.192\times 10^{11}\,s[/tex]
[tex]\Delta t \approx 22805.682\,yr[/tex]
The wood sample has an age of approximately 22800 years.
What happen when a piece of sodium is exposed in air?
Answer:
I literally got this from google.
Explanation:
In ordinary air, sodium metal reacts to form a sodium hydroxide film, which can rapidly absorb carbon dioxide from the air, forming sodium bicarbonate. ... In a comparatively dry atmosphere, sodium burns quietly, giving off a dense white caustic smoke, which can cause choking and coughing.
Happy almost Halloween! :)
Why doesn't air pressure crush an empty soft-drink can that is sitting on a table in your house?
Answer:
The air inside and outside are equal so air particles can go in and out. The can is empty so the air particles go in and out. That is why the can wont get crushed.
Explanation:
Air pressure does not crush an empty soft-drink can that is sitting on a table in your house as the pressure is equal outside and inside of the can.
What is pressure?Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.
There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .
It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.
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what is a family in a periodic table?
Answer:
A family is a vertical column .
The elements in a family have similar chemical properties.
PLS PLS PLS PLS PLS PLS PLS help ASAP!!!!! Scientists call all of the compounds that contain carbon and are found in living things Organic because ________.
WILL DO BRAINLIEST!
what do elements have to do with geology?
Answer:
Geology is the world... Elements make it up
Explanation:
Answer:
A lot of the elements are found in rocks, minerals, and well since they are elements make they make up everything on earth.
Explanation:
Question 5 of 5
Which two phrases describe the nature of an electromagnetic force?
O A. Acts only when objects touch each other
B. Produced by interactions between magnetic objects
O c. Not a fundamental force of nature
O D. Produced by interactions between electrically charged objects
Answer:
I think it's A and D
Explanation:
I'm not sure if it's right
Answer:
The answer is B and D
Explanation:
trust fr
How many moles of Sr2+ are present in 250 mL of a 0.45 M solution of strontium phosphide?
Moles of Sr²⁺ = 0.3375
Further explanationMolarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
[tex]\boxed{\bold{n=V\times M}}[/tex]
Strontium phosphide (Sr₃P₂)
Sr₃P₂ ⇒ 3Sr ²⁺ + 2P³⁻
mol of Sr₃P₂[tex]\tt 0.45~M \times 0.25~L=0.1125[/tex]
mol of Sr ²⁺mol ratio Sr₃P₂ : Sr ²⁺ = 1 : 3
[tex]\tt \dfrac{3}{1}\times 0.1125=0.3375[/tex]
The distribution coefficient between methylene chloride and water for solute Y is 14. An amount of 72.0 g of Y is dissolved in 180 mL of water. a) What weight of Y would be removed from water with a single extraction with 180-mL of methylene chloride? Report to 1 decimal place. b) What total weight of Y would be removed from water (the original solution) with two successive extractions with 90-mL portions each of methylene chloride?
Answer:
a)Weight of Y extracted from water in single extraction = 67.2 g
b) Total weight of Y extracted from water in two successive extractions = 70.9 g
Explanation:
Distribution coefficient, Kd = Cs / Cm
where Cs is concentration of solute in methylene chloride; Cm is concentration of solute in water
a) Let x g of solute Y be extracted into methylene chloride
72.0 - x g of Y will be left in water
Kd = (x/180 mL of methylene chloride) / (72.0 - x/180 mL of water) = 14
14 = 180 * x / 180 * 72.0 - x
x = 14(72.0 - x)
x = 1008 - 14x
15x = 1008
x = 1008/15
x = 67.2 g
Weight of Y extracted from water in single extraction = 67.2 g
b) First extraction: Let x g of solute Y be extracted into methylene chloride
72.0 - x g of Y will be left in water
14 = x/90 / 72.0 - x/180
14 = 180x/ 90(72.0 - x)
14 = 2x/ 72.0 - x
2x = 14(72.0 - x)
2x = 1008 - 14x
16x = 1008
x = 63.0 g
Second extraction: Amount of solute left in water after first extraction = 72 - 63 = 9.0 g
Let x g of solute Y be extracted into methylene chloride
9.0 - x g of Y will be left in water
14 = x/90 / 9.0 - x/180
14 = 180x/ 90(9.0 - x)
14 = 2x/ 9.0 - x
2x = 14(9.0 - x)
2x = 126 - 14x
16x = 126
x = 7.90 g
Total weight of Y extracted = (63 + 7.90) g
Total weight of Y extracted from water in two successive extractions = 70.9 g
a) The Weight of Y extracted from water in single extraction is 67.2 g
b) The Total weight of Y extracted from water in two successive extractions should be 70.9 g
Calculation of weight:Here
The distribution coefficient, Kd should be
= Cs / Cm
where
Cs should be a concentration of solute in methylene chloride;
Cm should be a concentration of solute in water
a) Let us assume x g of solute Y that should be extracted into methylene chloride
So,
72.0 - x g of Y will be left in water
And, now
Kd = (x/180 mL of methylene chloride) / (72.0 - x/180 mL of water) = 14
So,
14 = 180 * x / 180 * 72.0 - x
x = 14(72.0 - x)
x = 1008 - 14x
15x = 1008
x = 1008/15
x = 67.2 g
b)
Now First extraction:
Let x g of solute Y be extracted into methylene chloride
So,
72.0 - x g of Y will be left in water
14 = x/90 / 72.0 - x/180
14 = 180x/ 90(72.0 - x)
14 = 2x/ 72.0 - x
2x = 14(72.0 - x)
2x = 1008 - 14x
16x = 1008
x = 63.0 g
Second extraction:
Amount of solute left in the water after the first extraction that should be
= 72 - 63
= 9.0 g
Now
Let x g of solute Y be extracted into methylene chloride
9.0 - x g of Y will be left in water
14 = x/90 / 9.0 - x/180
14 = 180x/ 90(9.0 - x)
14 = 2x/ 9.0 - x
2x = 14(9.0 - x)
2x = 126 - 14x
16x = 126
x = 7.90 g
Total weight of Y extracted = (63 + 7.90) g
= 70.9g
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What is chemical energy? (2 points)
a
Energy that is stored or released during a chemical reaction
b
Energy that is destroyed during a physical change
c
Energy that is released during a phase change
d
Energy that is created when a substance is being burned
Answer: a
Energy that is stored or released during a chemical reaction
Explanation: a battery has chemical energy when u but in something that u can power with batteries it starts a chemical reaction.
Hope I helped :)
Explanation:
Chemical energy
Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place.
Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.
Having the same number of valence electrons means having similar chemical properties.
True or False
Answer:
True
Explanation:
Because atoms with the same number of valence electrons react in similar ways with other elements.
Calculate the number of moles of barium chloride in 427g of a 3.17%by mass barium chloride solution?a) 6.5x10^02molb) 7.83x10^02molc) 4.31x10^02mold) 7.81x10^02mole) 4.27x10^02mol
Answer:
The answer is "Option a".
Explanation:
Multiply the mass of the solutions by 3.17% to get the mass of [tex]BaCl_2[/tex]:
[tex]\to 427 \ g \times 0.0317 = 13.56\ g[/tex]
Divide this mass with BaCl2's molecular concentration to acquire the mole ratio:
[tex]molar mass = 208.24 \frac{g}{mol}\\\\moles = \frac{13.56}{208.24} = 0.065 \ moles \\\\[/tex]
[tex]= 6.5 \times 10^{-2} \ moles[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
A 427 g sample is 3.17% by mass barium chloride, that is, there are 3.17 g of barium chloride per 100 g of sample.
The mass of barium chloride in 427 g of the sample is:
[tex]427gSample \times \frac{3.17gBaCl_2}{100gSample} = 13.5gBaCl_2[/tex]
We can calculate the number of moles in 13.5 g of barium chloride using its molar mass (208.23 g/mol).
[tex]13.5 g \times \frac{1mol}{208.23g} = 6.5 \times 10^{-2} mol[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
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Explain how this chemical equation demonstrates the Law of Conservation of Matter (Mass).
Answer:
Explanation:
The equation must be balanced on both sides to show the law of conservation of mass. So, as long as it is equaled, the law is shown.
Which solution, NaCl(aq) or CH3OH(aq), conducts electricity?
Answer:
NaCl(aq)
Explanation:
Nacl(aq) is an electrolyte when it melts and it conducts electricity. This is due to the fact that when it is in solution, it dissociates to be Na+ and Cl-. These ions are conductors of electricity. It conducts electricity because of the movements and also the discharge of ions. CH3OH(aq) is not a conductor of electricity therefore the first option is the answer.
A petroleum refinery is producing the four products shown in the table. The table also shows the state of matter at room temperature of each of the substances. All of these compounds are molecular compounds consisting of only hydrogen and carbon. Which of the following products is likely to have the highest molecular weight? A. Natural gas B. Gasoline C. Jet fuel D. Paraffin wax
Answer:D
Explanation: in molecular solids, one factor that determines the strength of intermolecular forces is the mass of the molecules. Since all of these compounds only contain hydrogen and carbon we don’t have to worry about their polarities as they are all the same. Inter molecular forces tend to be stronger when the molecular weight is greater since paraffin wax is the only solid at room temperature it has the highest melting point
Answer: Your Answer Is D. Paraffin wax
Explanation:Hope This Helps!
How many atoms are in one formula unit of the compound FeC5O5?
O 10
05
12
O 11
Answer: D) 11
Explanation:
We have 1 iron atom (the Fe)
We have 5 carbon (denoted [tex]C_5[/tex])
We have 5 oxygen atoms (denoted [tex]O_5[/tex])
So we have 1+5+5 = 11 atoms in this compound.
In one formula unit of [tex]\rm FeC_5O_5[/tex], the number of atoms of oxygen has been 5. Thus , option B is correct.
Formula unit has been the empirical representation of the chemical compound. The formula has been responsible to deliver the information about the number of atoms of each elements present in the sample.
The given compound has been [tex]\rm FeC_5O_5[/tex]. The formula has subscript with each element representing the number of atoms. The atoms of each element has been:
Iron = 1Carbon = 5Oxygen = 5The number of atoms of oxygen present in one formula unit of [tex]\rm FeC_5O_5[/tex] has been 5. Thus , option B is correct.
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