Which are correct ???

Answer:

Accuracy is the closeness of a measured value to the accepted or exact value. The precision of a tool is the smallest unit of measure the tool provides. The smaller the units a tool can measure, the more precise the tool. A measurement can be precise and not be accurate.

Explanation:

Answer:

Correct

Explanation:

Balanced forces are always zero!

Answer:

Balanced

Zero

Explanation:

Answer:

76.5g is present in 2.55mol of diazine

Explanation:

no. of mole equals mass over molar mass

molar mass of diazine equals 30g/mol.. then substitute to get the mass in grams which is 76.5g

Answer:

speed

energy

Answer:

particle speed and particle energy

Explanation:

i just took the quiz on a p e x

Answer:

Conduction

Explanation:

Answer:

Conduction is correct

Explanation:

Elements that will loose electron as so that ion can be formed are; Fe and Pb.

Therefore, Metals usually lose electron while non- metals accept the electron.

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Hi , I’m really sorry because I just have the first question... so here it is :

So it is 0.52 mol .

Have a nice day .

Answer:

2 3 and 6

Explanation:

The sample of the liquid has more energy than the sample of solid. Hence, option B is correct.

Thermal energy refers to the energy contained within a system that is responsible for its temperature.

The particles in the liquid are the same as in the solid but they have more energy. To melt solid energy is required to overcome the attraction between the particles and allow them to pull them apart. The energy is provided when the solid is heated up.

Hence, option B is correct.

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Answer:

about 6 min

Explanation:

Answer:

B

Explanation:

Because the atomic mass is the mass of a single atom of a chemical elements

Answer:

15 cents where im from

Explanation:

molecule(s)

two or more atoms touching means they are connected as molecules which also make up compounds

Answer:

Pb²⁺(aq) --> Ni²⁺(aq)

Explanation:

The equation of the reaction is given as;

Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)

In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.

We have;

Pb²⁺(aq)  + NO₃²⁻(aq) -->  Ni²⁺(aq)  + NO₃²⁻(aq)

Canceling the spectator ions;

Pb²⁺(aq) --> Ni²⁺(aq)

Answer:

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Explanation:

The complete ionic equation of this reaction is

Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)

The nitrate ions are spectator ions and can be removed from the equation, giving us

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

F has a smaller radius than F− because F− has an additional energy shell  correctly compares the radii of F and F−. The correct option is C.

Thus, Compared to oxygen, fluorine is a stronger electronegative element. The outermost electrons of fluorine are gripped by the nucleus more tightly than oxygen because fluorine has a high electronegativity.

It takes more energy to remove the outermost electron of fluorine than it does to remove the outermost electron of oxygen. Fluorine has a higher ionization energy than oxygen as a result.

An atom's energy is determined by how much energy it gains or loses as a result of chemical processes that result in electron loss or gain. Exothermic reactions are those in which energy is released, and endothermic reactions are those in which energy is absorbed.

Exothermic reactions produce negative energy, which is why energy is given a negative sign.

Thus,  F has a smaller radius than F− because F− has an additional energy shell   correctly compares the radii of F and F−. The correct option is C.

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Answer:

Explanation:B ice melting is a phiyscal change and the mass of the substance remains the same

Answer:

b

Explanation:

Answer:

At pH 3.5:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the anion-exchange column.

At pH 6.5:

Peptide A with pI 5.1 will bind to the cation-exchange column, while peptide B with pI 8.5 will bind to the anion-exchange column.

At pH 10.8:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the cation-exchange column.

Explanation:

Ion-exchange column chromatography is used for separating proteins and other molecules in a solution based on differences in net  charge. Negatively charged molecules bind to positively charged solid supports called the anion-exchange column, whereas, positively charged molecules bind to  negatively charged solid supports known as cation-exchange column.

A peptide can acquire a net charge if the pH of the medium is either above or below its isoelectric point,pI. At pH above pI, the peptide acquires a net negative charge and can bind to a positive support. At pH above pI, the peptide acquires a net positive charge and can bind to a negative support. The greater the difference between pH and pI, the tighter the peptide will bind to the column.

At pH 3.5:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the anion-exchange column.

At pH 6.5:

Peptide A with pI 5.1 will bind to the cation-exchange column, while peptide B with pI 8.5 will bind to the anion-exchange column.

At pH 10.8:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the cation-exchange column.

Answer:cookie

Explanation:

The student would have success in experiment with using copper in a closed circuit as it allows conduction and is a good conductor of electricity.

Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.

In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .

When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:

1) heat conduction

2) electrical conduction

3)sound conduction

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Answer:

A

Explanation:

It is not c or b, D is not applicable so it must be A

Answer: The final concentration of a solution is 0.350 M

Explanation:

According to the dilution law,

[tex]C_1V_1=C_2V_2[/tex]

where,

[tex]C_1[/tex] = concentration of concentrated acid solution = 12.0 M

[tex]V_1[/tex] = volume of concentrated acid solution = 35.0 ml

[tex]C_2[/tex] = concentration of diluted acid solution= ?

[tex]V_2[/tex] = volume of another acid solution= 1.20 L = 1200 ml

( 1L=1000ml)

Putting in the values:

[tex]12.0\times 35.0=C_2\times 1200[/tex]

[tex]C_2=0.350M[/tex]

The final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L is 0.350 M

Answer:

i dont

Explanation:

Answer:

Endothermic

Explanation:

In order to melt the ice cube, heat is required, so the process is endothermic. Endothermic reaction In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings by the reaction.

Answer:

The Pressure Temperature Law. This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. With an increase in temperature, the pressure will go up.

Explanation:

Answer: The monoatomic ions formed by bromine and rubidium are [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

Explanation:

When an atom accepts an electron negative charge is created on atom and is called as anion.  When atom loses an electron positive charge is created on atom and is called as cation.

The atomic number of bromine and rubidium is 35 and 37 respectively. So, the number of electrons is equal to 35 and 37 respectively. Bromine will gain one electron and rubidium will lose one electron to attain stable electronic configuration to form [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

[tex]Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]

[tex]Br^-:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

[tex]Rb:37:1s^22s^22p^63s^23p^64s^23d^{10}4p^63s^1[/tex]

[tex]Rb^+:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

Answer:

Covalent compound

Explanation:

It is formed by covalent bonds, in which the atoms share a pair of valence electrons

Answer:

C

Explanation:

It’s the lowest to create storms

Answer:

both are same give different number

Answer:

Partial pressure of O₂ =  0.0198 atm

Partial pressure of He = 0.1584 atm

Explanation:

Given data:

Mass of oxygen = 80.0 g

Mass of helium = 80.0 g

Total pressure = 0.1800 atm

Partial pressure of each gas = ?

Solution:

First of all we will calculate the number of moles.

Number of moles of oxygen:

Number of moles = mass/molar mass

Number of moles = 80.0 g/ 32 g/mol

Number of moles = 2.5 mol

Number of moles of helium:

Number of moles = mass/molar mass

Number of moles = 80.0 g/ 4 g/mol

Number of moles = 20 mol

Total number of moles = 20 mol + 2.5 mol = 22.5 mol

Mole fraction of O₂ = 2.5 mol/ 22.5 mol = 0.11

Mole fraction of He = 20 mol / 22.5 mol = 0.88

Partial pressure:

Partial pressure of O₂ =  0.11× 0.1800 atm = 0.0198 atm

Partial pressure of He = 0.88 × 0.1800 atm = 0.1584 atm