Answer:
3. 39 39 54
Explanation:
Atoms are the smallest units of matter that have the characteristics of a chemical element. They consist of small particles called protons, electrons, and neutrons.
Protons are positively charged particles that make up the nucleus of the atom along with neutrons, neutrally charged particles. Their mass is almost the same - about 1 AMU (atomic mass unit). Electrons, the negatively charged particles, are much lighter than them and don't significantly contribute to the mass of the atom. Their mass is equal to about 1/2000 of the mass of a proton or neutron.
This is why we need to determine which atom out of the ones you were given has the highest number of protons and neutrons. The first has 91, the second 90, the third 93, and the fourth 91. This means that the third atom has the highest mass.
HELP HELP
There is only one type of receptor to sense stimuli
true or false?
they deserve a brainliest :)
enantiomeric pair and its application
Explanation:
Enantiomers are pairs of non-identical molecules that are non-superimposable mirror images of each other and that have at least one chiral carbon or chiral center, making them chiral compounds. They have similar chemical properties, except for when they interact with other chiral compounds.
The part of memory which temporarily holds information for later use is refered to as
A. clipboard. B. Clipart. C. Desktop. D. Flash disk
Answer:
D - Flash Disk
Explanation:
Which of the following aqueous solutions has the highest boiling point?
A) 0.10 M lithium sulfate, Li2SO4
B) 0.10 M hydrochloric acid, HCI
C) 0.10 M lithium nitrate, LINO3
D) 0.10 M magnesium sulfate, MgSO4
The highest boiling point : A) 0.10 M lithium sulfate, Li₂SO4
Further explanationSolutions from volatile substances have a higher boiling point and lower freezing points than the solvent
ΔTb = Tb solution - Tb solvent
ΔTb = boiling point elevation
[tex] \large {\boxed {\boxed {\bold {\Delta Tb \: = \: Kb.m}}} [/tex]
Kb = molal boiling point increase
m = molal solution
For electrolyte solutions there is a van't Hoff factor = i
i = 1 + (n-1) α
n = number of ions from the electrolyte
α = degree of ionization, strong electrolyte α = 1, for non electrolytes i = 1
So ΔTb ≈ i(van't Hoff), the greater i, the greater ΔTb
α = 1 , strong electrolyte
A) 0.10 M lithium sulfate, Li₂SO4
Li₂SO4 ⇒2Li⁺+SO₄²⁻ ⇒n=3
B) 0.10 M hydrochloric acid, HCI
HCl⇒H⁺+Cl⁻⇒n=2
C) 0.10 M lithium nitrate, LINO₃
LINO₃ ⇒ Li⁺+NO₃⁻ ⇒n=2
D) 0.10 M magnesium sulfate, MgSO4
MgSO4 ⇒ Mg²⁺ + SO₄²⁻ ⇒ n=2
Treatment of 2-amino-2-methylcyclohexanone with methyl 2,4-dibromobutanoate in the presence of a nonnucleophilic base, , involves two successive SN2 reactions and gives compound A. Propose a structural formula for compound A.
Answer:
Explanation:
The proposed structural formula for compound A can be seen in the diagram below with its reaction mechanism. In the first SN2 reaction, we could see how anime reacts with the primary alkyl bromide since it is more reactive. However, the product derived undergoes a subsequent SN2 reaction in the second stage to produce a cyclic product.
What type of reaction mechanism accounts for the reaction of an alkene with aqueous acid to give an alcohol
Answer: Electrophilic addition reaction
Explanation:
Alkenes are compounds which have at least one double bond between the carbon atoms in the molecule. This is an indication of a shortage of hydrogen atoms. The compound is said to be unsaturated. As an unsaturated compound alkene undergoes the following reaction:
-- Combustion reaction
-- Hydrogenation reaction
-- Addition reaction.
The addition reaction of alkenes occur due to the presence of pi electrons in which an electrophile attacks the carbon-carbon double bond to form the addition products. An electrophile is a molecule that has the affinity to react with other molecules containing a donatable pair of electrons.
A typical example of reaction between alkene and acid is in the decolourisation of acidified potassium tetraoxomanganate(VII) with ethene. The oxygen supplied to the reaction breaks the double bond to yield ethane 1,2 diol ( an alcohol).
The reaction of an alkene with the acid has been performed with the carbocation intermediate formation, followed by the nucleophilic substitution reaction.
The alkenes have been the hydrocarbons with the presence of one double bond in the structure. The double bond has been consisted of the pi electrons.
The alkene has been bonded with the pi-electron, thus in the chemical reaction the pi bond-breaking results in the partial negative and positive charge to the carbon atoms. The negative OH group has been the nucleophile that is attracted by the negatively charged carbon atom, and the bond formation results in the alcohol.
The reaction for an alkene with acid has been given in the image attached.
Thus, the reaction of an alkene with the acid has been performed with the carbocation intermediate formation, followed by the nucleophilic substitution reaction.
For more information about the reaction mechanism, refer to the link:
https://brainly.com/question/24924720
If two oxygen atoms bond covalently, the bond is
A) nonpolar ionic
B) nonpolar covalent
C) polar covalent
D) ionic
Answer:
probably b i got nothing but i hop eit is good
Explanation:
Which of Earth’s spheres contains rocks and sediments?
Answer:
Geosphere
Explanation:
Geosphere sometimes called as lithosphere starts from the surface of the earth and lies till crust. This part of the earth contains rocks and minerals.
This portion of the earth includes sediments,mountains and rock. The natural resources that is available to the human brings lies in geosphere.
How many moles are there in 1.0 g of H2?
Answer:
4-5
Explanation:
maybe 5
A teacher makes the following statement.
“Gasoline boils at a relatively low temperature (about 150°C). The kerosene is removed at around 200°C, followed by diesel oil at 300°C and fuel oil at around 370°C.”
What topic is the teacher most likely talking about?
distillation of a mixture
filtration of a pure substance
evaporation of a mixture
sorting of a pure substance
Answer:
distillation of a mixture
Explanation:
Answer:
A.) Distillation of mixture.
Explanation:
edge 2021
Please help I'm so confused
Methylphenidate is used to treat ADHD (attention deficit hyperactivity disorder). A patient is prescribed two 10.1 mg Methylphenidate tablets each day. Methylphenidate patches release Methylphenidate into the body by absorption through the skin. The patches come with different amounts of Methylphenidate. The maximum amount of Methylphenidate in one brand of patch supplies a patient with 20. mg of Methylphenidate per day.
Determine the amount of Methylphenidate a patient may take using 2 tablets (in mg) Be sure your answer has the correct number of significant figures.
Answer:
They work by increasing activity in the brain, particularly in areas that help control attention and behaviour. Methylphenidate is used to treat children with attention deficit hyperactivity disorder (ADHD). It helps with hyperactivity and impulsive behaviour, and allows them to concentrate better.
Explanation:
What organic product would you expect from the reaction of ethylmagnesium bromide (CH3CH2MgBr) with H2O.
Answer:
It would produce ethane (CH₃CH₃)
Explanation:
Ethylmagnesium bromide (CH₃CH₂MgBr) is a Grignard's reagent.
It is a highly reactive substance, and as any alkylmagnesium bromide
(R-CH₂MgBr) it reacts with water to produce an alkane (R-CH₃). R stands for any carbon structure bonded to that functional group.
Which of the following pairs of elements will not form an ionic bond with
each other.
Sodium and Argon
Calcium and Oxygen
Magnesium and Chlorine
Aluminum and Nitrogen
Answer:
Sodium and Argon
Explanation:
I don't understand
Answer:
A 9 moles of reactants changes into 11 moles of product
Explanation:
What would you expect the balance to read when the reaction has finished? Circle the correct answer.
179 g , 180 g , 181 g
Answer all of the questions pllllzzz
Answer:
180 g
Explanation:
At the end of the reaction, the mass is still expected to be 180g this is because in every chemical reaction, mass must be conserved.
According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroyed".
Bonds are broken and elements rearranged. The mass is thereby constantThe sum of the mass of the reactant is then even equal to the mass of the product derived.What is the significance of temperature t
Answer:
send a pic or more info
Explanation:
How many moles of helium gas are contained in a presurized gas cylinder with an internal volume of 10.0 L at a pressure of 8.91 atm and a temperature of 287.4 K?
Answer:
n = 3.77 mol
Explanation:
Given data:
Number of moles = ?
Volume of gas = 10.0 L
Pressure = 8.91 atm
Temperature = 287.4 K
Solution:
Formula:
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
by putting values,
8.91 atm × 10.0 L = n × 0.0821 atm.L/ mol.K ×287.4 K
89.1 atm.L = n × 23.60 atm.L/ mol
n =89.1 atm.L / 23.60 atm.L/ mol
n = 3.77 mol
determine the vapor pressure in atm of water in an aqueous solution of 12% BY MASS EHTYLEENE GLYCOL (ANITFREEZE) IF THE VAPOR PRESSURE OF
The given question is incomplete, the complete question is:
Determine the vapor pressure (in atm) of water in an aqueous solution of 12% by mass ethylene glycol (antifreeze) if the vapor pressure of pure water at that temperature is 0.095 atmospheres.
Answer:
The correct answer is 0.091 atm.
Explanation:
Based on the given information, the mass of ethylene glycol is 12% by mass, which means 12 grams of ethylene glycol dissolved in 88 grams of water.
The moles of a substance can be determined by using the formula,
Moles = Weight/molecular mass
Number of moles of water = mass/molecular mass
= 88g/18g/mol
= 4.88 moles
Number of moles of ethylene glycol = Mass/molecular mass
= 12 grams/62g/mol
= 0.193 moles
Mole fraction of water will be,
Mole fraction = number of moles of water/Number of moles of water+Number of moles of ethylene glycol
Mole fraction = 4.88/4.88+0.193
= 0.961
Vapor pressure of water can be determined by using the formula,
Vapor pressure = Vapor pressure of pure water * Mole fraction of water
= 0.095 * 0.961
= 0.091 atm.
Question 3
What is the pH of a solution with [H 30 +) = 1 x 10 -9 M?
1.0 x 10 -5
-9.0
5.0
-5.0
9.0
Answer:
[tex] \huge 9[/tex]
Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ { H_3O}^{+}][/tex]
From the question we have
[tex]pH = - log(1 \times {10}^{ - 9} ) [/tex]
We have the final answer as
9Hope this helps you
Determine the mole ratio between oxygen and water for the following equation:
2 H2 + O2 - 2 H2O
A. 1:2
B. 1:1
C. 2:2
D. 2:1
Answer:2.2
Explanation:
What happened when Crookes placed a solid object inside
the cathode ray tube?
a
The object cast a shadow on the other end of the
tube.
b The object exploded.
С
The cathode rays burned a small hole in the
object.
d The cathode ray tube stopped working.
What is neutralization ?
Answer:
"a chemical reaction in which acid and a base react quantitatively with each other"
Explanation:
Which of these elements has the highest first ionization energy?
a) As
b) Ga
c) Bi
d) Cs
e) K
Answer:
Cesium (Cs)
Explanation:
This eliment has an ionization energy of 3,8939
When glucose is reduced the product is
Select one:
a. maltose
b. glucitol
O c. galactose
O d. gluconic acid
e. sucrose
Answer:
b) Glucitol
Explanation:
The glucose loses the carbonyl group and its transformed to CH2OH
See Picture for Question. I have other questions as well.
Answer: here lol
Explanation:
hope it helps just read very carefully
how many moles are there in 1578 grams of Ba3(C6H6O7)2
Answer:
Explanation:
The essential though process is to ask oneself when converting grams to moles=> 'How many formula weights are in the given mass?' This directs one to divide the substance's formula weight into the given mass (in grams) on order to determine number of moles. That is ...
moles = Given Mass of Substance in grams / formula weight of substance in grams
= 1578 grams / 791 grams-mol.⁻¹ =1.995 mole ≅ 2 moles
classify the following as a heterogeneous, homogeneous, or a pure substance:
Lemonade with no pulp
Answer:
pretty sure it's heterogeneous
Explanation:
Also, I saw you added me as a friend and I'm kinda curious as to why :)
Answer:
Heterogeneous mixture
Explanation:
Using the activity series, the reaction 2Al+6HBr-2 AlBr3+3 H2 will only occur if.....Al is above Be on the periodic table or heat is added to the reaction or a precipitate forms or Al is above H on the activity series
Answer:
Al is above H on the activity series
Explanation:
The given chemical reaction is expressed as:
2Al + 6HBr → 2AlBr₃ + 3H₂
The reaction above is a single displacement or replacement reaction and will only occur if Al is above H on the activity series.
The driving mechanism of such reaction is the position of the species on the activity series. The higher an atom is the more reactive and easier it will displace the lower ones.How many oxygen atoms are contained in 4.39 grams of Al2(SO4)3?
The average distance between two molecules is 6.55 x 10 19 pm. What is this distance in nanometers? Report your number in scientific notation and with the correct number of significant figures. For example 1000 would be reported as 1.00e+3 and 0.001 would be 1.00e-3.
So there are two aluminum atoms, three sulfur atoms, and 12 oxygen atoms in a single unit of the compound Al2(SO4)3.
What is aluminum?Chemical element aluminum has the atomic number 13 and the letter Al assigned to it. The density of aluminum is around one third that of steel, which is less than that of most common metals. When exposed to air, it generates an oxidized layer that protects the surface because to its strong affinity for oxygen. With regard to color and light-reflecting properties, aluminum has a striking visual similarity to silver. It has a soft, ductile, and non-magnetic texture.
Aluminum is the twelfth most frequent element in the universe and has only one stable isotope, 27Al, which is also quite abundant. Radiodating employs the radioactivity of 26Al.
Chemically, aluminum belongs to the boron group and is a post-transition metal.
To learn more about aluminum from the given link:
https://brainly.com/question/11952150
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(30 POINTS AND BRAINLIEST, THIS IS DIMENSIONAL ANALYSIS! PLEASE HELP & SHOW WORK!) (only right answers otherwise I WILL REPORT)
In a primitive barter society, the following rates of exchange exist: 1 fot = 5 vum, 2 sop = 3 tuz, 4 bef = 5 tuz, and 9 fot = 2 bef. A man has 4 sop and wants to convert all his possessions into vum. How many vum can he trade for?
The number of vum the man can trade for is = 108 vum
Calculation of the number of vumThe number of sop the man has = 4 sop.
But the exchange rates are as follows:
1 fot = 5 vum,
2 sop = 3 tuz,
4 bef = 5 tuz,
9 fot = 2 bef
Using,
2 sop = 3 tuz,
4sop = X tuz
X tuz = 4×3/2 = 13/2 = 6 tuz.
Using,
4 bef = 5 tuz,
X bef = 6 tuz
X bef = 6×4/5
X bef =24/5 = 4.8 bef
Using,
9 fot = 2 bef
X fot = 4.8 bef
X fot = 9 × 4.8/2
X fot = 21.6 fot.
Using,
1 fot = 5 vum,
21.6 fot = X vum
X vum = 5 × 21.6/1
X vum = 108 vum
Learn more about exchange rates here:
https://brainly.com/question/25970050
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