Plzz help me well mark brainliest if you are correct

Answer:

Avogadro's constant says that  

1

mole of any atom contains  

6.022

⋅

10

23

atoms. In this case you have  

3.40

⋅

10

22

atoms:

3.40

⋅

10

22

atoms

6.022

⋅

10

23

atoms

mol

=  

5.65

⋅

10

−

2

m

o

l

Step 2

The atomic mass of helium (He) will give you the weight of one mole of this molecule:  

1

mol =  

4.00

gram:

4.00

g

mol

⋅

5.65

⋅

10

−

2

mol

=  

0.226

g

So the  

3.40

⋅

10

22

helium atoms weigh  

0.226

gram

.

Explanation:

Mark as brainlyiest

Answer:

Lithium Chloride would be the best one

Sodium Hydroxide would be the second best

Explanation:

Answer:

Nitrates compared to sulphates are much more soluble therefore won't form precipitates easily.

Answer:

True

Explanation:

Hydrogen bonding is a bond that exists between hydrogen and a highly electronegative element such as oxygen, nitrogen, fluorine etc.

The greater solubility of the triphenylphosphine oxide owes to the hydrogen bonded interaction between it and the 1-propanol.

The alkene lacks such hydrogen bonded interaction because it does not have a highly electronegative atom in its structure.

Hence, triphenylphosphine oxide is removed based on its polarity and hydrogen bonding ability.

Answer:

[tex]ZnCO_3(s)+2KNO_3(aq)[/tex]

Explanation:

Hello there!

In this case, for the referred reactants side, we can evidence that this is a double displacement reaction whereby Zn gets bonded with CO3 and therefore K gets bonded with NO3 to yield:

[tex]Zn(NO_3)_2+K_2CO_3\rightarrow ZnCO_3+2KNO_3[/tex]

Whereas the KNO3 product is aqueous and the ZnCO3 is solid due to the corresponding solubility rules. Thereby, the answer is the third one.

Regards!

Answer:

C

Explanation:

Answer:

The Periodic Table can be divided into s, d, p, and f sublevel blocks. For elements in the s sublevel block, all valence electrons are found in s orbitals. For elements in the p sublevel block, the highest energy valence electrons are found in p orbitals.

Explanation:

Answer: The net ionic equation is [tex]2H^+(aq)+2F^-(aq)+Ba^{2+}(aq)+2OH^-(aq)\rightarrow BaF_2(s)+2H_2O(l)[/tex]

Explanation:

The net ionic equation of any reaction does not include any spectator ions.

Spectator ions are defined as ions that do not get involved in a chemical equation. They are found on both the sides of the chemical reaction when it is present in ionic form.

The chemical equation for the reaction of hydrofluoric acid and barium hydroxide follows:

[tex]2HF(aq)+Ba(OH)_2(aq)\rightarrow BaF_2(s)+2H_2O(l)[/tex]

The ionic form of the above equation follows:

[tex]2H^+(aq)+2F^-(aq)+Ba^{2+}(aq)+2OH^-(aq)\rightarrow BaF_2(s)+2H_2O(l)[/tex]

There are no spectator ions in the ionic form.

The net ionic equation for the above reaction follows:

[tex]2H^+(aq)+2F^-(aq)+Ba^{2+}(aq)+2OH^-(aq)\rightarrow BaF_2(s)+2H_2O(l)[/tex]

Answer:

Explanation:

are where most bits of broken rock are deposited.

This is because oceans are where most bits of broken rock are deposited.

Answer:

1. Temperature,  the average kinetic energy of particles, indicates how warm something is. Thermal energy, or the overall kinetic energy of the particles, indicates how a substance or material will transmit heat or chill something else.

2. A thermal expansion is a matter to change in volume in response to a change in temperature.

3. Heat is the form of energy that is transferred between systems or objects with different temperatures.

4. Air temperature near or over bodies of water is much different from that over land due to differences in the way water and land heat and cool. Properties that affect water temperature are transparency, ability to circulate, and specific heat.

5. Radiation is the transfer of heat energy through space by electromagnetic radiation.

6.  Radiation is natural and found everywhere, it comes from outer space, the air we breathe, and the earth we tread.

7. When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. The fluid above a hot surface expands, becomes less dense, and rises.

8. Convection currents in the Earth occur in the mantle

9. The fire's heat causes molecules in the pan to vibrate faster, making it hotter. These vibrating molecules collide with their neighboring molecules, making them also vibrate faster.

10. Since air is a poor conductor, most energy transfer by conduction occurs right near Earth's surface. Conduction directly affects air temperature only a few centimeters into the atmosphere.

- Hope this helps!

Answer:

1.34 mol

Explanation:

Molarity, which is the molar concentration of a solution, can be calculated by dividing the number of moles (n) by the volume (V).

That is;

Molarity (M) = n/V

According to the information provided in this question;

M = 2.40M

V = 56.0 mL = 56/1000 = 0.056 L

Since molarity = n/V

number of moles = M × V

n = 0.056 × 24

n = 1.34 mol

Answer:

0.4 L

Explanation:

Calculate by using Boyle's Law P₁V₁=P₂V₂

(0.14atm)(2.4L) = (0.84atm)(V₂)

0.336 atmL = (0.84atm)(V₂)

V₂ = 0.336 atmL/0.84atm

V₂ = 0.4 L

Answer:

(C) the physical state of each reactant and product

Explanation:

Hope this helps

Answer:

Objects appear different colours because they absorb some colours (wavelengths) and reflected or transmit other colours. ... For example, a red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum

A red object appear red because it absorbs light of wavelengths other than red. Therefore, option C is correct.

The distance between identical points (adjacent crests) in adjacent cycles of a waveform signal propagated in space or along a wire is defined as the wavelength. This length is typically specified in wireless systems in meters (m), centimeters (cm), or millimeters (mm) (mm).

A transverse wave's wavelength is defined as the distance between two adjacent crests. A longitudinal wave's wavelength can be calculated as the distance between two adjacent compressions.

The wavelengths that are reflected or transmitted are what we see as colors. A red shirt, for example, appears red because the dye molecules in the fabric have absorbed light wavelengths from the violet/blue end of the spectrum. The only light reflected from the shirt is red light.

Thus, option C is correct.

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Answer:

False, Solubility increases with temperature for most solids.

Explanation:

Answer:  Formula: Mass = (Volume)(Density)

Iron Density = 7.87 g/cm^3

Volume of Iron = 55.2 cm^3

Mass=(V)(D)

Mass= (55.2 cm^3) x (7.87 g/cm^3)

Mass=  434,42 g

Explanation:

Iron has a density of 7.87 g/cm³. 434,42 g is the mass of 55.2 cm³ of iron.

The term density is defined as the measurement of how closely a material is packed together.

It is also defined as the mass per unit volume. Density Symbol is D or ρ Density Formula is ρ = m/V, where ρ is the density, m is the mass of the object and V is the volume of the object.

Density is an important because it allows us to find out what substances will float and what substances will sink when placed in a liquid.

Formula:

Mass = (Volume)(Density)

Given:

Iron Density = 7.87 g/cm³

Volume of Iron = 55.2 cm³

Mass=(V)(D)

Mass= (55.2 cm³) x (7.87 g/cm³)

Mass= 434,42 g

Thus, Iron has a density of 7.87 g/cm³. 434,42 g is the mass of 55.2 cm³ of iron.

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Answer:

D

Explanation:

Magnesium is more reactive than zinc so no reaction will take place

Answer:

80 ml

Explanation:

From the question,

Applying Dilution formular

MV = mv................... Equation 1

Where M = Molarity of Kl before dilution, V = Volume of Kl before dilution, m = molarity of Kl after dilution, v = volume of Kl after dilution.

make V the subject of the equation

V = mv/M............. Equation 2

Given: m = 1.00 M, v = 200 ml, M = 2.50 M

Substitute these values into equation 2

V = (1.00×200)/2.50

V = 80 ml

Explanation: where the article????

Answer: The percent yield of the reaction is 83.5 %

Explanation:

The given balanced equation is

[tex]SiO_2+3C\rightarrow SiC+2CO[/tex]

[tex]SiO_2[/tex] is the limiting reagent as it limits the formation of product and [tex]C[/tex] is the excess reagent.

According to stoichiometry :

60.08 g of [tex]SiO_2[/tex] produce = 40.11 of [tex]SiC[/tex]

Thus 50.0 of [tex]SiO_2[/tex] will produce=[tex]\frac{40.11}{60.08}\times 50.0=33.4[/tex]  of [tex]SiC[/tex]

 Experimental yield of SiC = 27.9 g

Percent yield = [tex]\frac{\text {Experimental yield}}{\text {theoretical yield}}\times 100=\frac{27.9g}{33.4g}\times 100=83.5\%[/tex]

Thus  percent yield of the reaction is 83.5 %

The percent yield of 83.5 % of 50.0 g of silicon dioxide is heated with an excess of carbon, and 27.9 g of silicon carbide is produced in the reaction.

The chemical equations are balanced when the reactants react to form products. The reactants and products react in proper ratios and if they are not in ratio then we balance them by adding the required quantity in the reactants and the products.

The given balanced equation is

[tex]\rm SiO_2+3C---- > SiC+2CO[/tex]

[tex]SiO_2[/tex] is the limiting reagent as it limits the formation of product and is the excess reagent.

According to stoichiometry

60.08 g [tex]SiO_2[/tex] of  produce = 40.11 of [tex]SiC[/tex]

Thus 50.0 of  [tex]SiO_2[/tex] will produce=  [tex]\dfrac{40.11}{60.08} \times 50=33.4\ SiC[/tex]

The experimental yield of SiC = 27.9 g

The percentage yield will be calculated as

[tex]\rm Percentage \ Yield = \frac{Experimental\ yield}{Theoretical \ yield }\times 100[/tex]

[tex]\rm Percentage \ yield =\dfrac{27.9}{33.49} \times 100=83.5[/tex]

Thus the percent yield of 83.5 % of 50.0 g of silicon dioxide is heated with an excess of carbon, and 27.9 g of silicon carbide is produced in the reaction.

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Answer:

When a molecule absorbs infrared radiation,transition s occur from the ground vibrational state to an excited vibrational state. For a molecule to be IR active there must be a change in dipole moment as a result of the vibration that occurs when IR radiation is absorbed.

Answer:

Al,Ga,B

Explanation:

Now since i helped you can you help me with this plz

Matteo took 5 math quizzes. The mean of the 5 quizzes was 8.2. Here are four of his quiz scores 7, 7, 8, 10. What is the 5th quiz score? Show work.

Boron ( B )

Aluminium ( Al )

Gallium ( Ga )

Answer:

[tex]\lambda =4.33x10^{-12}m=4.33pm[/tex]

Explanation:

Hello there!

In this case, since the speed, wavelength and mass of an electron are related via the the Broglie wavelength:

[tex]\lambda =\frac{h}{m*v}[/tex]

Thus, by plugging in the mass of the electron and the Planck's constant, we obtain the following wavelength:

[tex]\lambda =\frac{6.626x10^{-34}J*s}{9.11x10^{-31}kg*1.68x10^{8}m/s}\\\\\lambda =4.33x10^{-12}m=4.33pm[/tex]

Best regards!

The data set is missing in the question. The data set is given in the attachment.

Solution :

a). In the table, there are four positive examples and give number of negative examples.

Therefore,

[tex]$P(+) = \frac{4}{9}$[/tex]   and

[tex]$P(-) = \frac{5}{9}$[/tex]

The entropy of the training examples is given by :

[tex]$ -\frac{4}{9}\log_2\left(\frac{4}{9}\right)-\frac{5}{9}\log_2\left(\frac{5}{9}\right)$[/tex]

= 0.9911

b). For the attribute all the associating increments and the probability are :

  [tex]$a_1$[/tex]   +   -

  T   3    1

  F    1    4

Th entropy for   [tex]$a_1$[/tex]  is given by :

[tex]$\frac{4}{9}[ -\frac{3}{4}\log\left(\frac{3}{4}\right)-\frac{1}{4}\log\left(\frac{1}{4}\right)]+\frac{5}{9}[ -\frac{1}{5}\log\left(\frac{1}{5}\right)-\frac{4}{5}\log\left(\frac{4}{5}\right)]$[/tex]

= 0.7616

Therefore, the information gain for [tex]$a_1$[/tex]  is

  0.9911 - 0.7616 = 0.2294

Similarly for the attribute [tex]$a_2$[/tex]  the associating counts and the probabilities are :

  [tex]$a_2$[/tex]  +   -

  T   2    3

  F   2    2

Th entropy for   [tex]$a_2$[/tex] is given by :

[tex]$\frac{5}{9}[ -\frac{2}{5}\log\left(\frac{2}{5}\right)-\frac{3}{5}\log\left(\frac{3}{5}\right)]+\frac{4}{9}[ -\frac{2}{4}\log\left(\frac{2}{4}\right)-\frac{2}{4}\log\left(\frac{2}{4}\right)]$[/tex]

= 0.9839

Therefore, the information gain for [tex]$a_2$[/tex] is

  0.9911 - 0.9839 = 0.0072

[tex]$a_3$[/tex]     Class label      split point       entropy        Info gain

1.0         +                        2.0            0.8484        0.1427

3.0        -                         3.5            0.9885        0.0026

4.0        +                        4.5            0.9183         0.0728

5.0        -

5.0        -                        5.5            0.9839        0.0072

6.0        +                       6.5             0.9728       0.0183

7.0        +

7.0        -                        7.5             0.8889       0.1022

The best split for [tex]$a_3$[/tex]  observed at split point which is equal to 2.

c). From the table mention in part (b) of the information gain, we can say that [tex]$a_1$[/tex] produces the best split.