Answer:
2.5×10^20atoms
Explanation:
number of moles= number of particles/Avogadro's constant
number of particles=Avogadro's constant × number of moles
number of particles=(6.02×10^23) × (4.1×10^-4)
number of particles=2.5×10^20
The pressure of a 980.0 mL sample of gas at a constant temperature is increased from 0.4620 atm to
0.6320 atm. What is the final volume of the gas?
Answer:
P
1
V
1
T
1
=
P
2
V
2
T
2
Explanation:
P
1
V
1
T
1
=
P
2
V
2
T
2
, given a constant quantity of gas.
And thus,
P
1
×
V
1
×
T
2
V
2
×
T
1
=
P
2
, even given this format, we can see the problem is dimensionally sound. We do need to use
absolute temperature.
P
2
=
1.00
⋅
a
t
m
×
250
⋅
m
L
×
313
⋅
K
500
⋅
m
L
×
293
⋅
K
≅
1
2
⋅
a
t
m
.
Explanation:
(This is rly for science but there’s no category for that) Which statement best describes how scientists and engineers work together
in the research and development cycle?
O A. Engineers come up with scientific questions when they are
developing their design, and scientists do research to answer
them.
O B. Scientists test designs made by engineers and then use the
results to improve the designs.
C. Scientists develop a new technology, and then engineers test it by
doing experiments.
D. Engineers make a scientific discovery, and then scientists perform
research to verify it.
Answer:
A. Engineers come up with scientific questions when they are developing their design, and scientists do research to answer them.
How many electrons does GeH4 have
how many moles in 200 grams of Br
2.3g of lithium chloride in 500cm3 of solution
Answer:
0.109M
Explanation:
Find molarity of the solution:
Molarity is defined as the ratio between the moles of the solute (Lithium Chloride in this case) per liter of solution. To solve this question we have to find the moles of LiCl and its volume as follows:
Moles LiCl -Molar mass: 42.394g/mol-
2.3g * (1mol / 42.394g) = 0.0543 moles
Volume in liters:
500cm³ * (1L / 1000cm³) = 0.500L
Molarity:
0.0543 moles / 0.500L =
0.109M
H2O2 is what type of compound?
Which of the following statements is FALSE? *
a.Smog is a phenomenon brought about by natural events.
b.Forest fires may be caused by human activities or by natural events.
c.Volcanic eruptions may contribute large amounts of pollutants to the atmosphere.
d.Under normal condition, the greenhouse effect maintains a temperature that support life on Earth.
Answer:
A:smog is a phenomenon brought about by natural events
Explanation:
false because of how phenomenon it is smog did not bought phenomenon and natural events!!
DOES THIS HELPFUL?
How are radar and an approaching siren different? How are they similar?
A. Radar uses sound waves, and the siren uses radio, but both exhibit
the Doppler effect
B. Radar uses radio, and the siren uses sound waves, but both exhibit
the Doppler effect
C. The Doppler effect can be observed only with radar, but both
devices use sound waves.
D. The Doppler effect can be observed only in the approaching siren,
but both devices use radio.
Answer:
b
Explanation:
Radar uses radio, and the siren uses sound waves, but both exhibit the Doppler effect. Therefore, option (C) is correct.
What is Doppler's effect?Radar operates by emitting radio waves and measuring the reflected waves to detect objects and determine their velocity. On the other hand, an approaching siren emits sound waves that propagate through the air.
Both radar and an approaching siren exhibit the Doppler effect. The Doppler effect is the change in frequency or pitch of waves (sound or electromagnetic) when the source of the waves and the observer are in relative motion. In the case of radar, the Doppler effect is used to measure the velocity of objects based on the frequency shift of the reflected radio waves. Similarly, the Doppler effect is observed with an approaching siren as the sound waves compress and the frequency appears higher as the source approaches the listener.
Therefore, both radar and an approaching siren differ in the type of waves they use (radio waves vs. sound waves), but they share the characteristic of exhibiting the Doppler effect.
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Please help me I need help.
13) Which "conversion tool" below would you use to complete this
conversion?
. Which of these types of electromagnetic radiation has the lowest energy?
a. Radio waves
b. Visible light
c. Gamma rays
Is this correct??Pls help!!!
Answer:
C
Explanation:
Answer:
Yes, your answer is correct. B is correct :3
Help i’m taking a test!!
What new element is formed from the equation below? (Answer form is
MN:, AN: , S)
Answer:
Element Z
Explanation:
I hope this is correct and helps you!
How many moles are there in 100g of helium
Explanation:
so for this one u need to remember this equation and use it to find out moles= mass /mr . Mr of helium is 4
so moles= mass /mr
=100/4
=25 moles
hope this make sense:)
Which of the following processes is not an example of physical weathering?
A. acidification
B. abrasion
C. frost action
D. exfoliation
Answer:
acidification
Answer:
I think its A
Explanation:
Hope this helps: )
A leaking underground storage tank or wastewater pouring into a river from a pipe would be examples of
Answer:
Water pollution.
Explanation:
This is because water pollution refers to the release or disposal of harmful substances called contaminants which contaminate water bodies which include rivers, oceans, lakes e.t.c.. These harmful substances affect aquatic organisms and make water unfit for good use. This can lead to the death if aquatic lives in the water bodies, release of bad smells and make the water bad . A leaking underground storage tank or wastewater pouring into a river from a pipe can be a source of water pollution.
12. A. 2 g of ferrous sulphate crystals 5 points
are heated in a dry boiling tube. a)
Name and define the type of reaction
that has taken place. b) Write
balanced chemical equation for the
above reaction. c) List two main
observations of this reaction. B. A
shining metal 'M'on burning gives a
dazzling white flame and changes to
a white powder ‘N’. a) Identify ‘M'and
'N'. b) Name the type of reaction
taking place and write the balanced
chemical equation.
Answer:
A) Decomposition reaction.
Decomposition reaction is defined as a chemical reaction whereby a compound is broken down into 2 or more simpler substances.
B) 2FeSO4 + Heat > Fe2O3 + SO2 + SO3
C) - Gas evolution because a gas is part of the product
- Upon heating its colour gradually changes from pale green to reddish brown which implies a change in state
Explanation:
A) Name of the reaction is; Decomposition reaction.
Decomposition reaction is defined as a chemical reaction whereby a compound is broken down into 2 or more simpler substances.
B) The balanced chemical equation is;
2FeSO4 + Heat > Fe2O3 + SO2 + SO3
C) From experience, the 2 main observations of this reaction are;
- Gas evolution because a gas is part of the product
- Upon heating its colour gradually changes from pale green to reddish brown which implies a change in state.
Please help is for my final An example of a chemical change is-
evaporation of seawater
о
sublimation of dry ice (CO2)
melting of aluminum
burning wood reducing it to ashes
Explanation:
Souring of milk
Baking of cake
100 POINTS!!! AND BRAINLIEST!!!
This tree species was preserved as a fossil in the Arizona desert. The species is now extinct. Describe what the environment was like when the tree lived and how it is different now. Then, infer why this type of tree and other living things that lived with it are extinct.
Give examples of how land resources are used in a city setting
Answer:
Land resources such as gravel and bedrock are used to construct buildings, roads, and sidewalks. Land is also where city structures—such as buildings, roads, and sidewalks—are constructed. People use land resources such as bedrock and aggregate to construct buildings, roads, and sidewalks.
I hope this answer helps
How much energy is required to raise the temperature of a 300.0
gram block of lead from 22.3°C to 59.9°C? The specific heat of lead is
0.129 J/gºC.
Answer:
Q = 1455.12 Joules.
Explanation:
Given the following data;
Mass = 300 grams
Initial temperature = 22.3
Final temperature = 59.9°C
Specific heat capacity = 0.129 J/gºC.
To find the quantity of energy;
[tex] Q = mcdt[/tex]
Where,
Q represents the heat capacity.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
dt represents the change in temperature.
dt = T2 - T1
dt = 59.9 - 22.3
dt = 37.6°C
Substituting the values into the equation, we have;
[tex] Q = 300*0.129*37.6 [/tex]
Q = 1455.12 Joules.
What is the percent by mass of carbon in carbon dioxide (CO2)?
A. 27%
B. 33%
C. 43%
D. 73%
if 26.8g of copper (ll) chloride are dissolved in sufficient water to make 4.00 L of solution, what is the molarity of the solution? & what is the solvent?
Answer: Molarity of the solution is [tex]4.97 \times 10^{-2} M[/tex] and water is the solvent.
Explanation:
Given: Mass of solute = 26.8 g
Volume = 4.00 L
Now, moles of copper (II) chloride (molar mass = 134.45 g/mol) are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{26.8 g}{134.45 g/mol}\\= 0.199 mol[/tex]
Molarity is the number of moles of a substance divided by volume of solution in liter.
Therefore, molarity of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.199 mol}{4.00 L}\\= 0.04975 M\\= 4.97 \times 10^{-2} M[/tex]
Solvent is defined as a component which is present in higher amount in a solution. Generally, a solvent is present in liquid state but it can also be a solid or gas.
In the given solution, copper (II) chloride is dissolved in water so copper (II) chloride is the solute and water is the solvent.
Thus, we can conclude that molarity of the solution is [tex]4.97 \times 10^{-2} M[/tex] and water is the solvent.
1) Escribe oraciones coherentes que incluyan los siguientes términos con los conceptos correspondientes:
CARBÓN-PETRÓLEO-GAS NATURAL-RECURSO NO RENOVABLE-
COMBUSTIBLES FÓSILES-HIDROCARBUROS-RESERVAS-CONTAMINACIÓN-
MAREAS NEGRAS
La respuesta correcta para esta pregunta abierta es la siguiente.
Estas son las oraciones apropiadas.
El carbón, el petróleo, y el gas natural son recursos naturales no renovables.
Estos generadores naturales de energía son considerados combustibles fósiles que produce la mayor parte de hidrocarburos que se usan en el mundo. Sin embargo, estas reservas energéticas se están agotando porque son recursos naturales no renovables. Además, estos combustibles son altos generadores de contaminación como es el caso de las mareas negras.
Independientemente de estas ideas, es apropiado decir que los combustibles fósiles han sido fuertemente cuestionados por los ambientalistas y los científicos porque son causantes del llamado calentamiento global y del cambio climático.
Por esa razón, la sociedad y los expertos ambientalistas están pidiendo que los gobiernos comiencen a utilizar más energías alternativas y renovables como la energía solar y las turbinas de viento o energía eólica.
If the graph of y = a x 2 + b x + c does not intersect the x -axis, then what is true about the roots? Both are real roots. Both are real roots. Both are imaginary roots. Both are imaginary roots. One is a real root, and one is irrational. One is a real root, and one is irrational. One is a real root, and one is rational.
Answer:
Both roots are imaginary roots.
Explanation:
Consider these things:
If we try to solve x²+1 = 0, notice that we aren't able to solve the equation in Real Number system because there are no negative outputs for quadratic function.
Remember that quadratic function has range greater or equal to the max-min value.
x-axis plane represents the solutions of that equation. If a graph intersects x-axis plane then it has a solution.
While a graph that doesn't have any intersects on x-plane, it means that the equation for that graph doesn't have real solutions but imaginary solutions.
As you may notice some of parabola graph has one intersect, two intersects or none. One intersect is one solution to the equation — Two intersects are two solutions of the equation and lastly, no intersects mean that no real solutions and remain only imaginary solution.
If a system is left to change spontaneously, in what state will it end?
A. The state with the lowest possible energy consistent with the state of maximum disorder
B. the state with lowest possible energy
C. The same state in which it began
D. The state with the maximum disorder
Answer:
The state with the lowest possible energy consistent with the state of maximum disorder
so letter A
If a system is left to change spontaneously then, the state with the lowest possible energy is consistent with the state of maximum disorder. option A is correct.
what is spontaneous change?A spontaneous change may be so fast or rapid or in a fraction of time that it is essentially instantaneous or fast or so slow that it cannot be observed over any practical time of period.
A is the spontaneous change is one in which the system happening into which the A an increase or boost in internal energy B lowering decline in entropy C lowering in energy D no energy change Medium.
The time-evolution or change of a system in which it releases free energy and it moves to a lower, or decreased more thermodynamically stable energy state, closer to attend the thermodynamic equilibrium.
Therefore, the system is left to change spontaneously then, and the state with the lowest possible energy is consistent with the state of maximum disorder. option A is correct.
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why do different people have differently shaped proteins?
The sequence of amino acids in the chain determines how the chain will fold up to make the protein, so different proteins have different three-dimensional shapes. ... This is because proteins form attachments and interact with many other molecules and structures inside organisms.
Write out a “for every” statement that relates the amount of methane to the amount of oxygen gas (CH4 + 2O2 = CO2 + 2H2O)
Answer:
For every one molecule of methane, one molecule of oxygen is required to release one molecule of CO2 and 2 molecule of H2O
Explanation:
As we can in the balanced equation below -
CH4 + 2O2 = CO2 + 2H2O
One molecule of CH4 reacts with two molecule of oxygen to release one molecule of CO2 and 2 molecule of H2O.
Hence, it can be said
For every one molecule of methane, one molecule of oxygen is required to release one molecule of CO2 and 2 molecule of H2O
How many days does it take the moon to orbit the Earth once.
Answer:
27.3 days
Explanation:
I really have no explanation lol.
Answer:
Hope thia helps
Explanation:
it takes 27.3 days!!!
explain what conservation of mass is and how to calculate it