Answer:
To reduce the bending of the railway
Explanation:
During summer(heat) metals tend to expand in size. The skits/gaps are present in the railway so that the metal could expand without causing bending of the railway track.
I need help with b) c) and what is the electronic configuration of atom E
Answer:
(b) A and C belongs to same group.
(c) D is a non metal.
Explanation:
The Electronic Configuration of E is
[tex]1s {}^{2} 2s {}^{2}2p {}^{6} 3s {}^{2} 3p {}^{6} 4s {}^{2} [/tex]
what are the 2 main methods of combination of elements??
Answer:
to make them react to each other to form a compound
Explanation:
mark me as brainliest pls
Answer:
An element is a material that consists of a single type of atom. Each atom type contains the same number of protons. Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.
which orbital has the lowest energy
Answer:
s orbital
Explanation:
it has the lowest energy because
Paulis law state that orbitals with lower energy must be fill first before that of higher energy
and the s orbital is filled first
Why doesn’t the KHP concentration have to be exactly 0.100M? Explain using complete sentences.
Answer:
The answer is in the explanation.
Explanation:
The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.
The reaction that explain this use is:
KHP + NaOH → KNaP + H2O
where 1 mole of KHP reacts per mole of NaOH
That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added
With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.
The moles of KHP are obtained from the volume and the concentration as follows:
Volume(L)*Concentration (Molarity,M) = moles of KHP
If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.
What is the correct equilibrium constant expression for the following reaction?
2NCl3(g) Û N2g) + 3Cl2g
Answer:
K = [N2] [Cl2]³ / [NCl3]²
Explanation:
The equilibrium expression, K, of a reaction:
aA + bB ⇄ cC + dD
Is defined as the ratio between the multiplication of concentrations of products powered to its reaction coefficient and the multiplication of concentrations of reactants powered to its reaction coefficient as follows:
K = [C]^c[D]^d / [A]^a[B]^b
Now, for the reaciton:
2NCl3 ⇄ N2(g) + 3Cl2(g)
K is:
K = [N2] [Cl2]³ / [NCl3]²
Question 10 of 10 A certain seed is surrounded by a sticky coating. It is fairly dense and does not float in water. How is this seed most likely spread?
A. It is dispersed by the wind, and it sprouts after it falls to the ground
B. It drops to the bottom of a body of water, where it sprouts.
C. It attaches to the fur of an animal, and it sprouts after it falls from the animal's fur.
D. Animals eat it, and it is deposited in their waste.
Products formed when chlorine is produced by the electrolysis of concentrated sodium chloride solution
The products formed during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
ELECTROLYSIS is the process by which electrolytes allows electric current to pass through it and is decomposed on the process.
CHLORINE is an element which can be produced industrially through the process of electrolysis of brine (concentrated sodium chloride solution). When sodium chloride is dissolved in water, it's ions separate and are capable of conducting electricity.
The products formed during this process includes:
chlorine sodium hydroxide and hydrogen gas.CHLORINE: this is released at the positive electrode during electrolysis. It is used for the following purposes:
it is used for sterilisation of water for domestic and industrial use it is used as a bleaching agent for cotton, linen and wood-pulp.SODIUM HYDROXIDE: this remains in the solution during electrolysis. It is used for the following:
processing food products, removing pollutants from water and manufacture of paper.HYDROGEN GAS:this is released at the negative electrode during electrolysis. this is used for the following:
manufacture of ammonia, hydrochloric acid and methanol it serves as constituents of many gaseous fuels such as water gas and coal gasTherefore other products during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.
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Convert 48,987 minutes to years
using the method of dimensional analysis
Answer:
Explanation:
48000 minutes [ 1 hour / 60 min ] 1 day / 24 hours ] [365 days / year]
48000 * [ 1/(60 * 24 * 365)]
48000 * [1 / 525600]
There are 0.0930954years in 48000 minutes
why do we shake syrup medicines before drinking
Answer:
The label may instruct you to shake a liquid medicine before using so that the active ingredients are evenly distributed throughout it.
Explanation:
Answer:
maybe because if somehow the liquids get separated then shaking them up would mix them back to how they are suppose to be originally.
Explanation:
potassium permanganate + water = ? which product will they form,and in which phase is it?
KMnO4 + H2O = MnO2 + O2 + KOH
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Tenemos una disolución de HNO3 cuya pureza es del 65% y tiene una densidad de 1.32 g/mL. ¿Cuál es la molaridad de la disolución? PM HNO3 = 63.0 g/mol.
Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].
El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.
Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.
Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.
Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:
[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]
Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].
Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:
[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]
En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]
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https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsthe first attempt to classify the elements was made by newlands true or false
Answer:
True. An English scientist by the name of John Newlands tried to classify the elements in a unique manner. He first started by arranging all the elements in a ascending order according to their atomic weights.
write an importance of endothermic reactions
Answer:
the uses of exothermic reactions are:
1) lighting of stove
2) self heating cans
3) hand warmers
4) in some case exothermic process can be used to cook food such as rice (by adding calcium oxide to water heat is evolved and it helps to cook food )
Explanation:
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what is chemistry?????
Answer:
chemistry - the science that studies the properties of substances and natural fenomens .
...........
Answer:
The Basic definition of Chemistry is:-
Chemistry is the scientific study of the properties and behavior of matter. It is the natural science that covers the elements that make up matter to the compounds that is composed of atoms, molecules and ions.
2. School bus accidents are very rare, possibly because they are so easy to see.
School buses have been around since 1915, but the official color of bright
yellow wasn't used until 1939. Would grey school buses get in more accidents?
Help plz!!!
Answer:
Grey school buses would likely get in more accidents because other drivers are expecting a yellow bus to make frequent stops and the lights and stop sign are noticeable on a brighter color.
Explanation:
yellow buses are easier to see in fog than a grey bus
Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
Answer:
ionic
Explanation:
I'll put the rest if the answers in comments
Answer:
1. Metallic bonds are responsible for many properties of metals, such as conductivity. Why is this possible?
*The bonds can shift because valence electrons are held loosely and move freely.*
2. Between which types of elements do ionic bonds occur, and how do electrons act within the bond?
*metals and nonmetals, electrons transferred*
3. Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?
*ionic*
4. Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?
*four covalent bonds*
5. How many covalent bonds is nitrogen (Group 5A) likely to form?
*three*
These are all the answers to the Bonds Quick Check.
Noble gases are the least reactive elements on the periodic table.
A. True
B. False
Answer:
The statement is True!"Why?"The Noble Gases have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.
Hope this helps!
Which of the following is true of science? (2 points)
It can be disproven by philosophy and religion.
It does not change after new evidence is discovered.
It is based on the personal opinions of scientists.
It is based on testable and replicable evidence.
Answer:
It is based on testable and replicable evidence.
what is a cubic unit cell ?
cubic unit cell is the smallest repeated unit which have all angles equal to 90 and all have edge lengths equal
It is the type of the Unit cell which is having all angles equal to 90 and all sides equal to each other
it's is a unit cell with cubic structure
Please help I have been stuck on this problem for a couple hours and can't figure it out
Answer:
11.92 Liters O₂(g) at STP
Explanation:
For most stoichiometry problems, if one will convert all given data into moles, solve by rxn ratios, then finish by converting to needed dimensions to complete problem.
2Pb(NO₃)₂ => 2PbO + 4NO₂ + O₂
Given 237.5 grams PbO formed in reaction = 237.5 g/223.2 g/mole = 1.064 mole PbO
From equation ratios, moles O₂ formed = 1/2(moles PbO) = 1/2(1.064 moles O₂) = 0.532 mole O₂
0.532 mole O₂ = 0.532 mole x 22.4 liters/mole at STP = 11.91756272 liters (calculator answer) ≅ 11.92 liters O₂ at STP (4 sig.figs. based on given 237.5g PbO)
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
The boiling point of water is 100ºC. The boiling point of acetone is 56ºC. Which statement about distilling a mixture of acetone and water is correct?
Acetone remains in the original container.
Water will vaporize from the mixture before acetone.
Acetone is captured and cooled.
Water is collected as it leaves the mixture.
Answer:
Acetone is captured and cooled.
Explanation:
The boiling point of acetone is lower than that of water, so it will vaporise before water. Then acetone will be captured and cooled to separate it from its mixture with water.
The statement which is correct about distilling a mixture of acetone and water is as follows:
Acetone is captured and cooled.Thus, the correct option is C.
What is Distillation?Distillation may be defined as a procedure that generally involves the conversion of a liquid into a vapor that is eventually condensed back to liquid form. With the help of this process, the separation of components or substances from a liquid mixture by using selective boiling and condensation occurs.
Acetone has the lowest boiling point as compared to water. So, it boils faster than that water and vaporizes before water. After the termination of this process, the acetone will be predominantly captured and cooled to separate it from its mixture with water.
Therefore, the correct option for this question is C.
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Can someone plz help me :<
Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens
Explanation:
why does an endothermic reaction require a greater activation energy than an exothermic one?
Answer:
in most of the endothermic reactions the atoms gains electrons from one to another. since the atom gains electrons there is a electron repulsive force between the host and the guest electron . As stability is inversely proportional to electron repulsive force the atom gains energy to attain stability .
The endothermic reaction mostly come under electron affinity
Explanation:
hope this helps you
if I am wrong just correct me
How many pounds of force is 240 Newtons?
Answer:
53.9541 pound force...
Show the comparative structure of union Parishad and Pourahava in chart.
Answer:
how will I show?
Explanation:
pLS teacher me
Which atom would be neutral?
1an oxygen atom with 16 electrons, 18 protons, and 16 neutrons
2an oxygen atom with 4 electrons, 6 protons, and 4 neutrons
3an oxygen atom with 9 electrons, 8 protons, and 8 neutron
4an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
A proton has a positive charge and an electron has a negative charge. Magnitude of both of these charges is same. So, we need the same number of electrons and protons to make the atom neutral.
Neutron is neutral, so we can safely ignore it in this question.
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
Classify the crystalline solids
full answer
crystalline solids are the type of solid which have long term arrangement of particle
they have sharp melting and boiling point
Answer:
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PLZ HELP ME
Which of these is an example of an example factor which affects the earths climate?
A - Decrease in the suns energy.
B - Warm and cold ocean currents.
C - Increase in atmospheric dioxide.
D - Release of dust during volcanic eruption
Answer:
D- Release of dust during volcanic eruption
Explanation:
During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.
answer:
a - decrease in the suns energy.
explanation:
although the other options do discuss climate, temperature, etc., the sun DIRECTLY influences the earth's climate and would most likely affect it on a larger scale. for example, warm and cold ocean currents would affect the temperature of the ocean and could touch bay cities or islands, but they would not dictate the overall climate of the earth :)
♡ hopefully my reply helped you come to an answer~ please keep in mind that my response is purely that... MY response! i still have lots to learn, so please correct/educate me if you have found otherwise ♡
Which of the following molecules contains six bonding electrons?
A C2H4
B CO2
C H2S
D NCl3
Answer:
c2h4 (etthane........
bexcuse it has 6 bond of hydrogen
C₂H₄ molecules contains six bonding electrons. Therefore, option A is correct.
What do you mean by the term bonding ?Chemical bonding is the process through which two or more atoms, molecules, or ions establish a chemical link to create a chemical compound. The atoms in the resultant molecule are held together by these chemical bonds.
Chemical bonds have three basic characteristics that must be taken into account: their strength, length, and polarity. The distribution of electrical charge among the atoms connected by a bond determines its polarity.
C₂H₄ molecules has six bonding electrons. This molecule is called as Ethylene. When bonding is done between two atoms, each atom shares a pair of electrons with each other.
Hence, for every one bond, two electrons are shared between two atoms
Thus, option A is correct.
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