Which of the following is true with respect to energy in a closed system?
A.
Energy can be destroyed, but cannot be created.
.
Energy can be created, but cannot be destroyed.
B.
OOOO
C. The system's kinetic energy must equal its potential energy.
D.
The total amount of energy in the system always stays the same.
Answer:
D. The total amount of energy in the system always stays the same
Explanation:
In the closed system, the total amount of energy in the system always stays the same.
What is closed system?Closed system is a arrangement in which exchange of energy or any material is restricted.
If any reaction is carried out in a closed system then energy of the system may convert from internal energy to potential or from potential to kinetic energy. But the total energy of the closed system is always remain same as before and after the reaction.
Hence option (D) is correct.
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Do S and Na have the same number of
electron shelis?
Answer:
Yes
Explanation:
Sulfur and Sodium will have the same number of electron shells.
Electronic configuration of
k l m
Na = 2 8 1
S = 2 8 6
We see that the have the same energy level.
Also, they belong to the same period on the periodic table. Elements in the same period will have equal number of shell.
A chemist titrates 100.0 mL of a 0.3065 M aniline (C6H5NH2) solution with 0.5774 solution at 25 . Calculate the pH at equivalence. The of aniline is .
Answer:
4.91
Explanation:
From the given information:
The millimoles of aniline = 100* 0.3065 = 30.65
30.65 millimoles HNO3 must be added to reach the equivalence point.
30.65 = V x 0.5774
V = 30.65/0.5774
V = 53.08 mL HNO3 must be added
Thus, total volume = 53.08 + 100 = 153.08 mL
[salt] = 30.65 / 153.08 = 0.20022 M
At equivalence point :
pOH = 1/2 [pKw + pKb + logC]
pOH = 1/2 [14 + 4.87 + log 0.20022 ]
pOH =9.086
pH = 14 - 9.086
pH = 4.914
pH ≅ 4.91 to 2 decimal places.
What kind of reaction is 2H202
>
2H20 + O2?
Answer: Disproportionation reaction
Explanation: A reaction where a compound undergoes oxidation as well as reduction. 2H2O2=2H2O + O2 here hydrogen peroxide is oxidized to oxygen and is reduced to water.
Answer: B (Decomposition)
Explanation: A P E X X X
Describe the motion of particles in a substance as thermal energy is added
Answer: it moves faster
Explanation:
When heat is added it gains thermal energy therefore it moves faster as things heat up and it loses thermal energy when it gets cooler causing particles to move slower
PLSSSSSSSSSSSSSSSSSSSSSSSSSS HELP
Which of the following best describes physical weathering? (4 points)
A series of chemical changes that wears away at rocks
The movement of rocks from one area to another
Any large-scale event such as volcanic eruptions or earthquakes
A process that breaks down large rocks into smaller piec
Answer:
D. A process that breaks down large rocks into smaller pieces.
Explanation:
Physical weathering if referred to the process of rocks breaking apart without changing their chemical composition. If you look at the other answers, none of them match the description of physical weathering.
Answer:
A process that breaks down large rocks into smaller pieces.
27. The fundamental SI unit of length is the meter. How-
ever, we often deal with larger or smaller lengths or
distances for which multiples or fractions of the fun-
damental unit are more useful. For each of the fol-
lowing situations, suggest what fraction or multiple
of the meter might be the most appropriate mea-
surement.
a. the distance between Chicago and Saint Louis
b. the size of your bedroom
c. the dimensions of this textbook
d. the thickness of a hair
Answer:
A) Km
B) m
C) cm
D) mm
Explanation:
A) The distance between Chicago and Saint Louis is quite a distance and would be best presented in the largest multiple of the SI unit of length.
For example if the distance is 500000 m, it's a bit bogus to write, so we can simplify by writing in terms of 10^(-3) m which is in km.
Thus, we can write as 500000 × 10^(-3) km = 500 km
B) By standard measurement, the size of a bedroom is usually: 3.6 m × 3.6 m.
This not complex to write and can be kept as it is in metres.
C) The average dimension of a textbook is around 0.25 m by 0.2 m.
Let's get rid of the decimal by converting to terms of 10² m which is expressed as cm.
Thus, dimension is now: (0.25 × 10²) by (0.2 × 10²) = 25 cm by 20 cm
D) Average thickness of a hair in metres is 8 × 10^(-5) m.
Now this is a bit long. So we can express is in terms of 10^(3) m which is an expression denoted by millimeter (mm).
Thus, thickness is 8 × 10^(-5) × 10³ = 0.08 mm
Dana is trying to determine if an unknown sample is a pure substance or not. The sample has a cloudy white color, and it seems evenly mixed throughout. The sample is a liquid with high viscosity. Dana tried separating the sample with a magnet with no effect. When Dana filtered the sample, larger granules of the sample were left behind in the filter. What evidence allowed Dana to conclude that the sample is NOT a pure substance?
It has a cloudy white color.
The liquid has high viscosity.
Dana tried separating the sample with a magnet with no effect.
Dana filtered the sample and larger granules of the sample were left behind.
Answer:
Dana filtered the sample and larger granules of the sample were left behind.
Explanation:
If a substance is pure, it will have a uniform composition throughout. It will not separate into particles of various sizes.
One of the characteristics of pure substances is that they are homogeneous. A mixture is definitely made up of particles of various sizes.
Since the particles was filtered and larger granules were left behind, the sample has been separated by a physical method (filtration). Only a mixture can be separated by physical methods. It is not a pure substance.
Which term refers to the ability to do work? O energy O power force O motion
Please I have a 50 question Exam
Answer:
the correct answer in energy
Explanation:
The term refers to the ability to do work is energy. The correct option is A.
What is energy?Energy is the quantitative property that is required by the body to do some work. It is a conserved quantity, but can not be created or destroyed.
Animals and plants get energy from food.
Thus, the correct option is A. energy.
Learn more about energy
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NEED HELP ASAP 7th grade science btw pls
Answer: the answer is A or Tributaries, River system and rivers
Explanation: Its A i had the same question last year for my 10th grade assignment
What type of clothing would you need to wear if you could visit the mesosphere
The type of clothe that you would wear when visiting the mesosphere are the winter clothes.
What is mesosphere?Mesosphere is used to describe the coldest part of the earth whose temperature is -85°C.
An individual that wants to visit such a cold area should wear clothes that would provide such with warmth such as the winter clothes.
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A molecule composed of two or more different
kinds of atoms is a (an)
Compare a mixture and a compound. How are they alike?
Contrast a mixture and a compound. How are they different
Answer:
1.Difference.
Mixtures are physically combined and can be separated by physical means while compounds are chemically combined and are separated by chemical means.
2.Mixtures do not have mixed boiling and melting points while compounds have mixed boiling and melting points.
2.Similarity.
Both mixtures and compounds are composed of two or more substances or elements combined.
Both can be separated.
Mixtures and compounds are alike in the following ways:
1. Both mixture and compound contains two or more substances.
2. Both mixture and compound can be separated.
3. Both mixture and compound have physical properties.
Differences between mixture and compound:Mixtures and compounds are different in the following ways:
1. A mixture contains two or more substances that are not chemically combined together while a compound contains two or more substances chemically combined together.
2. A mixture can be separated by physical methods while a compound can only be separated by chemical methods.
3. Mixtures can not be represented using a chemical formula. Compounds can be represented by chemical formula.
4. Examples of mixtures include: milk, kerosene in water etc. Examples of compounds include water, sodium chloride etc
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NEED HELP ASAP!!!!! PLEASE HELP!!!!! NEED HELP ASAP!!!!!
Directions: Name the covalent compound created.
EXAMPLE- Sr3P2= Tristrontium diphosphide
CH4 =
B2Si =
N2O5 =
CO2 =
Answer:
CH4 - Methane
B2Si - Diboron monosilicide
N2O5 - Dinitrogen pentoxide
CO2 - Carbon dioxide
Explanation:
When it comes to naming covalent compounds, there are several rules.
The name is derived based on the formula. For example, N2O5. The first element is nitrogen. To the name of the element, you add the prefix that tells us how many of its atoms are in the compound. In this case, there are two atoms, which means that the prefix will be di- (dinitrogen). The second element is oxygen. You are supposed to take only the root of the second element's name and then add the prefix denoting the number of its atoms and the suffix -ide (pentoxide). This is how we'll get dinitrogen pentoxide.
The only exception is methane (CH4), which is an organic compound. Organic compounds are named using the IUPAC nomenclature.
Which of the following is not a subatomic particle?
O Electron
O Neutron
O Nucleus
O Proton
The nucleus is not a subatomic particle, but rather made of the subatomic particles of protons and neutrons. An electron is also a subatomic particle, but it is not found in the nucleus. There are many other subatomic particles, but your teacher probably won't go over those terms until later.
Name 3 sources of carbohydrates for the production of an alcoholic drink
Answer:An alcoholic drink is a drink that contains ethanol, a type of alcohol produced by fermentation of grains, fruits, or other sources of sugar. The consumption of alcohol plays an important social role in many cultures. Most countries have laws regulating the production, sale, and consumption of alcoholic beverages.
Explanation: vodka the preferred alcoholic beverage of choice among alcoholics? #3 Doesn't make you feel bloated or full like beer does. It goes down quickly and smooth. #4 Gets you drunk just as fast as any other hard liquor can, and obviously much faster than beer or wine.
which element requires the least i.e. potassium or gallium why
Answer:
Potassium
General Formulas and Concepts:
Chem
Reading a Periodic TablePeriodic TrendsIonization Energy - energy required to remove an electron from a given elementCoulomb's LawShielding EffectZ-effective and Forces of AttractionExplanation:
The Periodic Trend for 1st Ionization Energy is increasing up and to the right. That means He would have the highest I.E and therefore take the most amount of energy to remove an electron.
Potassium and Gallium are both in Period 4. Potassium is element 19 and Gallium is element 31.
Potassium's electron configuration is [Ne] 4s¹ and Gallium's electron configurations is [Ne] 4s²3d¹⁰4p¹. Since both are in Period 4, they have the same number of core e⁻. Therefore, the shielding effect is the same.
However, since Gallium is element 31, it has 31 protons compared to Potassium, which is element 19 and has 19 protons. Gallium would have a greater Zeff than Potassium as it has more protons. Therefore, the FOA between the electrons and nucleus of Ga is much stronger than that of K. Thus, Ga requires more energy to overcome those FOA to remove the 4p¹ e⁻. Since K has less protons, it will have a smaller Zeff and thus less FOA between the e⁻ and nucleus, requiring less energy to remove the 4s¹ e⁻.
AS HEIGHT INCREASES SO DOES
Answer:
potential energy (im positive that its right)
What is the temperature of a gas if the container has a volume of 2,300 mL, with a pressure of 932 mmHg and 3.51 moles?
Answer:
The preceding temperature is equivalent to approximately 9.6 K => -263.5 °C
Explanation:
Given the provided problem, the formula may be substituted by the corresponding values:
Pressure (P)= 932 mmHg ==> 1.2 atm
Volume (V) = 2,300 mL ==> 2.31 L
Moles (n) = 3.51 moles ==> 3.51 mol
Proportional constant of ideal gas constant: (R) = 0.08206
Therefore, we can equate the following:
T= (PV)
nR
T= (1.2 atm · 2.31 L)
(3.51 mol · 0.08206)
T= 9.6 K ==> -263.5 °C
Thus, the cumulative temperature given the substituents/substance is equivalent to -263.5 °C.
Sodium thiosulfate mixed with hydrochloric acid makes a green precipitate is this a physical or chemical change?
a. Physical
b. Chemical
Can someone help me answer this I will give you brainliest
Answer:
I don't know the answer you can search it on Google you will get it and don't forget to follow me and mark me as brainlest please I will follow u back really if u follow me back
Answer:
It is chemical Change
Explanation:
Because you are changing the substance.
do you think the mass of the products after the chemical reaction would be greater than, less than, or the same as the mass of the reactants before the chemical reaction?
It will be the same, as explained by conservation of mass.
hope this helped!
Level 1: You are attempting to identify an unknown substance. Use the table to
answer the questions below.
Substance
Formula
Mass,
Color
Physical
State
Density Boiling
. (g/cm) Point,
Methane
CH
16.0
Gas
Colorless
0.423
-161.5
Ammonia
NH,
17.0
Gas
Colorless
0.70
-33
Unknown
???
???
???
???
???
???
Propane
CH
Gas
Colorless
0.493
-42.1
Bromine
Br.
159.8
Liquid
Red
4.04
58.8
Lithium
Li
6.94
Solid
0.534
1342
Silvery,
white
metal
Magnesium Mg
24.3
Solid
1.74
1090
Silver,
white
metal
Which of the following would most likely cause a chemical reaction to occur at a slower rate?
Answer:
D
Explanation: When you chill a substance when it is mixed with another substance, ( chilled vinegar mixed with sodium bicarbonate will react slower for instance) it reacts slower do to the molecules slowing down when chilled.
[tex]\huge\boxed{Option D}[/tex]
Solution:a liquid mixture in which the the solute which is in a smaller proportion is uniformly distributed within the the solvent which is the major component is called a solution.
_____________________________________Option AStirring the substance together vigorously:It increases the rate of reaction, because when we stir the solute in the solution, the mixed solute particles are distributed more further than when they are left stationary, making the environment (which surrounds the solute) less concentrated by the dissolved solute thus the rate increases and more solute is mixed.
Option BDissolving the reacting substance in water:No, A reacting substances in water are those which can react with water that are Ionic metal. Water is made of ions [tex]H^+ and OH^-[/tex]. Substances(solute), they mix or dissolve more because Solutes ions interact with the ions of a water(solvent), thus breaking the bonds between the solute and then ions of solute form bond with the ions of water. Thus the rate increases in water.
Option CIncreasing the temperature increases the rate of reaction:No, because by the increase in temperature, the kinetic energy of more molecules of a substance increase which results in reaching the threshold energy(minimum energy required by the molecules to change into product) of more molecules. So less molecules are left with low energy.
Option DDecreasing the temperature decrease the rate of reaction.Yes, the rate of reaction decreases because the molecules are slower and collide less. Less molecules make the effective collisions due to which the kinetic energy of molecules is less, so less molecules make up to the threshold energy. So decrease in temperature lowers the rate of the reaction.
_____________________________________Best Regards,'Borz'describe the Rutherford model... and and what are its limitation...
going offline forever ✌️
Answer:
Limitations of Rutherford Atomic Model
Although the Rutherford atomic model was based on experimental observations it failed to explain certain things. Rutherford proposed that the electrons revolve around the nucleus in fixed paths called orbits. ... Ultimately the electrons would collapse in the nucleus.
A person is pushing a box with a mass of 25 kg. If it accelerates at 0.3 m/s2, what is the force being applied to the cart?
Answer:
The answer would be 80kg
Explanation:
Have a good day.
Centripetal acceleration is in a
How are convalent molecules named?
Covalent compounds are named by using numerical prefixes to identify the number of atoms in the molecule. E.g. Mono, Di, tri, tetra, etc.
In the naming, never use mono- for the first element.
The first element keeps its name.
The second element always end in the suffix -ide.
Drop the double vowel for the prefix and the element of the second element in the compound.
Hope this helped!
What is the mass of HF produced by three reaction of 3.0 10 to the 23 molecules of H2 with excess F2
Answer:
It is 20. g HF
Explanation:
H2 + F2 ==> 2HF ... balanced equation
Since the question is asking us to find the mass of product formed, we will want to first convert the molecules of H2 into moles of H2 (we could do this at the end of the calculations, but it's just as easy to do it now).
moles of H2 present (using Avogadro's number):
3.0x1023 molecules H2 x 1 mole H2/6.02x1023 molecules = 0.498 moles H2
From the balanced equation, we see that 1 mole H2 produces 2 moles HF. Therefore, we can now find the theoretical mass of HF produced from 0.498 moles H2:
0.498 moles H2 x 2 moles HF/1 mol H2 = 0.996 moles HF formed.
The molar mass of HF = 20.01 g/mole, thus...
0.996 moles HF x 20.01 g/mole = 19.93 g HF = 20. g HF formed (to 2 significant figures)
Help pleasee I need help to write the formulas i’m so lost
Answer:
NH4
Explanation:
Match the term with the example that shows its definition [please].
Compressibility
Flammability
Heat of combustion
Toxicity
A) The burning of coal releases heat
B) Gasoline catches fire
C) Gas is squeezed into a small container
D) High lead levels in a lake kill fish