An atom of an element is shown by the model. A gray circle is surrounded by 4 concentric circles. The innermost circle has gray dots at the north and south positions; the second ring has 8 equally spaced dots, aligning with the inner ring at north and south; the third ring has 14 dots, equally spaced, aligned with the other rings at north and south; the outer ring has dots at north and south. How is this model useful? It shows how electrons are distributed in the shells of an iron atom. It shows how electrons are distributed in the shells of a cobalt atom. It shows how orbitals are distributed in the shells of an iron atom. It shows how orbitals are distributed in the shells of a cobalt atom.

Answer:

Both have densities greater than that of water

Explanation:

The ability of objects to either float or sink in a liquid depends on their relative densities.

If an object is denser than a liquid it will completely sink in it, but if the density of the object is less than that of the liquid, it will sink until the weight of liquid displaced is equal to the weight of the object, then it will finally float in that liquid.

In the case of the stone bead and iron beads dropped into a cup of water, hey both sank to the bottom because they are denser than water.

Answer:

The answer is "choice 2".

Explanation:

Its glycosidic fruit juice facility would be a chromosomal hydrogen bond and an aldehyde (or acetone) team generated from the intramolecular creation of the acetals (or ketal).

Its two heterocycles created at the anomeric core from of the 2 potential stereochemical are named anomers, that's why choice "has a downward projection (from terminal CH2OH party on the opposite side)" is correct.

Answer:

B. distance light travels in a year

got it on edge :)

The statement which accurately and best describes a light-year is the total distance which light travels in a complete year

Velocity of light can simply be defined as that fundamental constant that represents the speed of electromagnetic radiation in a vacuum.

The velocity of light = 2.9979 × 10^10cm/s

So therefore, the statement which accurately and best describes a light-year is the distance which light travels in a complete year

Learn more about light-year:

https://brainly.com/question/1224192

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Answer:

B

Explanation:

The main aim of lab rules is to minimize the no of accidents

Answer:

Basic

Explanation:

The pH scale is a scale that tells us about the concentration of hydrogen ions in a solution.

Acids have many hydrogen ions. Acids have a pH of less than 7.

Bases have fewer hydrogen ions and more hydroxide ions.  Bases have a pH of less than 14.

If the solution has a pH of exactly 7, then it is pure water. Water has the same concentration of hydrogen and hydroxide ions.

The antacid tablet has a pH of roughly 9.5 Since this is less than 14, but not equal to or less than 7, this must be an base. Therefore, it is considered to be in the basic range.

Answer:

9.5 is a base

Explanation:

A ph of less than 7 is an acid

7 is neutral

7 to 14 is a base

9.5 is a base

Answer:

22

Explanation:

22

Answer:

The correct option is;

(B) 1 s², 2s², 2p⁶, 3s², 3p³

Explanation:

The electron configuration is the outline of the electron arrangement about a nucleus

In the systemic pattern of electron arrangement within an atom, there are, s, p, d, f orbitals

The maximum number of electrons in an s, p and d orbital = 2, 6, and 10 respectively

Based on Aufbau's principle the electrons are arranged based on the order of their energy level

The charge is presented by the number of electrons in the outermost shell, an element able to form an ion of charge of -3 will gain 3 electrons to complete its outermost shell

Among the options given, option B is the only option that has the capacity to take the electrons to complete the number of electrons in the p orbital outermost shell to 6 from 3, that is 3p³ + 3e⁻→ 3p⁶.

Answer:

The correct answer is 5021.25 kJ/mol octane

Explanation:

The heat absorbed by the calorimeter is given by:

heat absorbed = Ccal x ΔT

Given:

Ccal = 6.18 kJ/ºC (heat capacity of calorimeter)

ΔT= Final temperature - initial temperature = 41.5ºC-22.0ºC = 19.5ºC

We first calculate the heat absorbed:

heat absorbed = 6.18 kJ/ºC x 19.5ºC = 120.51 kJ

The change in internal energy (ΔE) is equal to the heat absorbed by the calorimeter. In order to determine ΔE in kJ/mol we have to divide the heat into the number of moles of octane (C₈H₁₈) burned in the calorimeter.

Molecular weight (C₈H₁₈) = (12 g/mol x 8) + (1 g/mol x 18) = 114 g/mol

Moles of C₈H₁₈= mass/molecular weight= (2.75 g)/(114 g/mol)= 0.024 moles

Finally, we calculate ΔE:

ΔE = heat absorbed/moles of octane = (120.51 kJ)/(0.024 mol octane) = 5021.25 kJ/mol octane

Answer: A. 3 mol [tex]Cl_2[/tex] 3 mol Al:

Explanation:

Te given balanced chemical equation is :

[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]

According to the stochiometry :

A: 3 mol [tex]Cl_2[/tex] 3 mol Al:

3 moles of chlorine reacts with 2 moles of aluminium

B. 2 mol [tex]Al[/tex] 3 mol [tex]Cl_2[/tex]:

2 moles of aluminium  reacts with 3 moles of chlorine

C.  2 mol [tex]AlCl_3[/tex] 2 mol Al

2 mol of aluminium produces 2 mol of [tex]AlCl_3[/tex]

D. 3 mol [tex]Cl_2[/tex] 2 mol [tex]AlCl_3[/tex]

3 moles of chlorine produces with 2 moles of [tex]AlCl_3[/tex]

Thus the conversion factor not used for mole to mole calculations is  3 mol [tex]Cl_2[/tex] 3 mol Al:

Answer:

The given hydrocarbon is Butanol

Answer:

Weight = mass × earth's gravitational acceleration

Explanation:

Follow the following steps to measure the mass and weight of an object:

Answer:

Option D. T

Explanation:

Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:

Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)

ΔH = Hp – Hr

From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.

Therefore, the enthalpy change of the reaction is T.

Answer:

About 2 liters

Explanation:

Since 1 gallon equals 3.785 liters, you figure out how many liters per week she uses by 3.785 x 0.75 which is 2.83875. Then divide that by 7 which is 0.405535 liters per day. Then multiply that by 5 days which is 2.027 liters in 5 days.

Answer:

the answer is 5.1 1049 mol.

Answer:

1) 0.1077 moles

2) 137043.2 moles

3) 180.186 grams

4) 6.53×10²² molecules or formula units

5) 1.505×10²³ ions

6) 90.626 grams

7) 0.555 moles

Explanation:

1) The number of moles, n = Mass of the substance/(Molar mass of the substance)

The molar weight of PO₄⁻³ is 94.971 g/mol

The number of moles in 10.23 g of PO₄⁻³ is n =10.23/94.971 = 0.1077 moles

The number of moles in 10.23 g of PO₄⁻³ = 0.1077 moles

2) The number of molecules of Na₂CO₃ in one mole of Na₂CO₃ is given by the Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ molecules

Therefore, the number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ is found by determining how many Avogadro's number of molecules are in 8.25 × 10²⁸ molecules of Na₂CO₃ as follows;

The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = (8.25 × 10²⁸)/(6.02 × 10²³) = 137043.2 moles

The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = 137043.2 moles

3) The molar mass of CH₂O = 30.031 g/mol

Therefore, the mass of 6 of CH₂O = 6 moles × 30.031 g/mol = 180.186 grams

The mass of 6 of CH₂O = 180.186 grams

4) The molar mass of NaCl = 58.44 g/mol

The number of moles of NaCl in 6.34 g of NaCl 6.34/58.44 = 0.1085 moles

1 formula unit of NaCl = 1 molecule of NaCl

The number of molecules in one mole of  a substance =  [tex]N_A[/tex] = 6.02 × 10²³

Therefore, the number of molecules in  0.1085 moles of NaCl = 6.02 × 10^(23) × 0.1085 = 6.53×10²² molecules or formula units

5) The number of ions per mole of any substance is give by Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ ions,

The number of ions in 0.25 moles of Cu⁺² = 0.25×6.02 × 10²³ ions = 1.505×10²³ ions

The number of ions in 0.25 moles of Cu⁺² =  1.505×10²³ ions

6) The molar mass of CH₄ = 16.04 g/mol

The number of moles, n, in 3.4×10²⁴ = 3.4×10^(24)/(6.02×10^(23)) = 5.65 moles 5.65*16.04

The mass of 5.65 moles of CH₄ = 5.65 moles × 16.04 g/mol = 90.626 grams

The mass of 3.4×10²⁴ molecules of CH₄ = 90.626 grams

7) The density of water = 1 g/mL

The volume of the water 10 mL

The mass of the water = Volume × Density = 10 mL × 1 g/mL= 10 grams

The molar mass of water = 18.015 g/mol

The number of moles of water in 10 g  of water = mass/(Molar mass) = 10/18.015 = 0.555 moles.

Answer:

Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.

Explanation:

Answer:

Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.

Explanation:

PLATO exact answer

Answer:

ingredient. U.s unit. SI unit. SI unit(540)

flour. 2cups. ²/6. 180cups = 1.8×10²

milk. 2cups. ²/6. 180cups. =1.8×10²

eggs. 2. ²/6. 180eggs. =1.8×10²

melted butter. ⅓cup ¹/18. 30cups. =3×10¹

sugar. 1spoon. ¹/6. 90spoons. =9×10¹

baking powder 2spoons ²/6. 180spoons. =1.8×10²

salt. ½spoon. ¹/12. 45spoons. =4.5×10¹

Explanation:

1) to get the SI unit divide the U.S unit by 6

example:eggs = 2÷6. =²/6

2) to get the SI unit for 540 people ,multiply the SI unit by 540.

example:eggs ²/6×540. = 180

3)convert the answers to scientific notation

example:eggs =180. =1.8×10²

Answer:

The correct answer is - the second law of thermodynamics.

Explanation:

The second law of thermodynamics says that the in all heat energy exchange or transfer, and if there is no gain or lose of energy in a system, the potential energy of the particular state in that system will less than that of initial state of the system in any case.

It also suggests that the processes deals with the conversion of the heat energy are irreversible and the energy can be transfer from lower temperature system to higher temperate system without adding energy.

Thus, The fact that a heat pump requires energy to move heat from a colder object to a hotter object is a real life example of the second law of thermodynamics.

Answer:

Protons, Electrons, Neutrons

Explanation:

Neutron: 0 or Neutral

Electron: -1 or Negative

Proton: +1 or Positive

For proton and neutron look at neutr for neutral and p for positive

Answer:

❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

The answer is Protons, Electrons, Neutrons

There is three of them.....

Hope this will help you

❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

Explanation:

Answer:

it's a chemical Element

Explanation:

symbol He

atomic number 2.

The question is incomplete, the complete question is;

To make a table of the elements, dimitri Mendeleev sorted the elements according to their?

Answer:

Atomic weights

Explanation:

Dimitri Medeleeve is a Russian scientist who worked assiduously on the project of developing a system of classifying all the elements. His periodic table was filled with spaces as many atoms weren't yet discovered. 'Eka' prefix was used to name some elements whose properties closely resembled that of their predecessors in Mendeleev's system of classification.

The dependence of the atomic properties on the weight of the atom was the basis for Mendeleeves' original classification. According to Medeleeve, elements having similar chemical properties are also expected to have similar atomic weights and their atomic weights was found to increase regularly.

The Mendeleeve concept of periodic arrangement of elements is the closest precursor of the modern periodic table as it is used in chemistry. Mendeleev arranged the elements in order of increasing relative atomic mass .

Answer:

100mL of chloromethane

Explanation:

Based on the equation:

Cl₂(g) + CH₄(g) → HCl(g) + CH₃Cl(g)

1 mole of chlorine reacts per mole of methane to produce 1 mole of HCl and 1 mole of chloromethane

Avogadro's law says that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. Using Avogadro's law we can say of the equation that:

1 mL of chlorine reacts per mL of methane to produce 1 mL of HCl and 1 mL of chloromethane

Because the system stays under constant pressure and temperature.

As 100mL of Cl₂ reacts with excess of CH₄ and 1mL of Cl₂ produce 1mL of CH₃Cl there are produced:

Answer:

Explanation:

The graph shows the phase diagram of water . From it , it is clear that at 100°C water remains in equilibrium with water vapour and at this temperature , the vapour pressure is equal to one  atm . So this must be boiling point of water.

At 0.7 atm pressure , boiling point must have been reduced . So when water is at 100°C , it must have been completely in vapour phase .

Now the pressure is increased to 1.4 atm . In this process of increase of pressure , the water in vapour state must have turned into liquid state as soon as the pressure increases beyond  1 atm . Beyond it its boiling point would have increased above  100°C so it can not remain in gaseous phase . At 1.4 atm , its boiling point would have increased to 110°C or so . Hence it must be in liquid phase because its temperature is below its boiling point at that pressure .

Hence water changes from gaseous phase to liquid phase when pressure changes from 0.7atm to 1.4 atm .

Answer: 0.938 moles of [tex]ZnCl_2[/tex] will be produced.

Explanation:

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]

moles of zinc:

[tex]\text{Number of moles}=\frac{61.0g}{65g/mol}=0.938moles[/tex]

[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]

As HCl  is in excess , zinc is the limiting reagent and it limits the formation of product.

According to stoichiometry :

1 mole of Zn produce =  1 mole of [tex]ZnCl_2[/tex]

Thus moles of  Zn produce = [tex]\frac{1}{1}\times 0.938=0.938[/tex] moles of [tex]ZnCl_2[/tex]

Thus 0.938 moles of [tex]ZnCl_2[/tex] will be produced.

Answer:

Explanation:

GIven that:

The activation energy = 250 kJ

k₁ = 0.380 /M

k₂ = ???

Initial temperature [tex]T_1 =[/tex] 1001 K

Final temperature [tex]T_2 =[/tex] 298 K

Applying the equation of Arrhenius theory.

[tex]In \dfrac{k_2}{k_1 }= \dfrac{Ea}{R}( \dfrac{1}{T_1 }- \dfrac{1}{T_2})[/tex]

where ;

R gas constant = 8.314  J/K/mol

[tex]In \dfrac{k_2}{0.380 }= \dfrac{250 * 10^3}{8,314}( \dfrac{1}{1001 }- \dfrac{1}{298})[/tex]

[tex]In \dfrac{k_2}{0.380 }= -70.8655[/tex]

[tex]\dfrac{k_2}{0.380 }= e^{-70.8655}[/tex]

[tex]\dfrac{k_2}{0.380 }= 1.67303256 \times 10^{-31}[/tex]

[tex]{k_2}= 1.67303256 \times 10^{-31} \times {0.380 }[/tex]

[tex]{k_2}= 6.3575 \times 10^{-32}[/tex]  /M .sec

Half life:

At 1001 K.

[tex]t_{1/2} = \dfrac{In_2}{k_1}[/tex]

[tex]t_{1/2} = \dfrac{0.693}{0.38}[/tex]

[tex]t_{1/2} =[/tex] 1.82368 secc

At 298 K:

[tex]t_{1/2} = \dfrac{0.693}{6.3575 \times 10^{-32}}[/tex]

[tex]t_{1/2} =1.09 \times 10^{31} \ sec[/tex]

Answer:

The answer is B

Explanation:

Answer:

Hello!

Your answer is B) Ca(HCO3)2!!

Explanation:

Hope this helps you!!

itsMATT04

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Explanation:

ascorbic acid is lemon

lemon contain ascorbic acid....

it is organic acid.....

Answer:

4

Explanation:

none of them

they are compounds and mixtures

Answer:

4. none of them

Explanation:

Water is a compound.

Air is a mixture.

Soil is a mixture.

None of them are elements.

Answer:

1:put these in sneaker and add water since sulphur is insoluble and the sugar will dissolve and the sand will settle obtain the sulphur

2:filter the mixture of sand and sugar solution to obtain the sand as residue and solution as filtrate

3:using an evaporating dish evaporate sugar solution to saturation not dryness to get crystals.

Answer:

Molarity = 2.0833 M (Approx)

Explanation:

Given:

Number of moles (n) = 0.25

Volume of solution = 120 ml = 0.12 L

Find:

Molarity

Computation:

Molarity = Number of moles (n) / Volume of solution.

Molarity = 0.25 / 0.12

Molarity = 2.0833 M (Approx)