What is the atomic number of silicon​

Answer:

The pair of arrows which represents the relationship of speeds of the two cars is;

The second option as shown in the attached drawing

Explanation:

The given parameters are;

The reading on the speedometer of one car = 20 m/s

The reading on the speedometer of the other car = 72 km/h = 20 m/s

The blue arrow = 20 m/s

Therefore, given that the speeds of both cars are equal (20 m/s = 72 km/h = 20 m/s),  the pair of arrows that represent the relationship of speeds of the two cars is two equal length blue arrows which is the second option

The attached diagram showing the pair of arrows that represents the relationship of speeds of the two cars is drawn using Microsoft Visio.

Explanation:

moles=mass÷molar mass

n=m÷Mr

6.0=14.6÷Mr

Mr=14.6÷6.0

Molar mass= 2.433

Answer:

VALENCE ELECTRONS are involved in the bonding of atoms

Explanation:

Hope that helps

Answer:

Antonie van Leeuwenhoek used single-lens microscopes, which he made, to make the first observations of bacteria and protozoa. His extensive research on the growth of small animals such as fleas, mussels, and eels helped disprove the theory of spontaneous generation of life.

Explanation:

Hope this helps and have a great day :)

Answer:

C. Hydrogen Ions.

Explanation:

The pH level of soils is measured based upon the acidity or basicity level in the soil. The pH scale usually measures between 0-14. 7 is the neutral pH level of soil and a pH level below 7 is considered acidic and above 7 is alkaline.

So, soil with a high amount of hydrogen ions (H+) will be considered acidic. As the amount of hydrogen ions increases in the soil, the pH level of the soil decreases, making it acidic.

Therefore, option C is correct.

Answer:

SiH4

Explanation:

4 hydrogens serve a the base and the Si is on top which forms a tetrahedral shape.

First, it combines with carbon dioxide in the soil to form a weak acid called carbonic acid. ... Carbonic acid slowly dissolves away minerals in rock, especially the carbonate minerals that make up limestone and marble. The weak acid decomposes the insoluble rock into watersoluble products that move into the groundwater.

Answer:

12.736 grams of hydrogen peroxide

Explanation:

Moles of Carbon dioxide : n = 4.037 x 10⁻³

Given

2.43 x 10²¹ molecules of Carbon dioxide

Required

Moles

Solution

1 mol = 6.02 x `10²³ particles(molcules, atoms, ions)

Can be formulated :

N = n x No

n = moles

No = Avogadro's number 6.02 x `10²³

moles of Carbondioxide :

n = N/No

n = 2.43 x 10²¹ / 6.02 x `10²³

n = 4.037 x 10⁻³

Answer:

B its most likely sorry if im wrong :D :(

Explanation:

Answer:

An ideal gas is a theoretical concept and a real gas behaves in an ideal manner under conditions which includes a high temperature and a low pressure such that the gas has high kinetic energy, and the intermolecular forces between the molecules are weak

The Ideal Gas Law is P·V = n·R·T

Where;

P = The pressure of the gas

V = The volume of the gas

n = The number of moles of the gas

R = The Universal Gas Constant

T = The temperature of the gas

For a gas cooled to 10 Kelvin and placed under high pressure, the interaction between individual gas molecules increases, and the kinetic energy of the gases is much lower and more comparable to the inter molecular forces between the gas molecules, which in turn produces observable changes from the initial ideal behavior of the gas such that the gas behavior deviates from the Ideal Gas Laws appreciably and are better modelled by the Van der Waals Equations which takes into account, the volume the gas particles occupy and the intermolecular forces between the molecules

The Van der Waals equation is presented as follows;

[tex]P = \dfrac{R \cdot T}{V - b} - \dfrac{a}{V^2}[/tex]

Where;

V = The molar volume

a = The gas constant a represents the attractive forces between the gas particles

b = Represent the volume occupied by the particles of the gas

Explanation:

Answer: A, B, & C

Explanation:

A. The ideal gas model assumes that gas particles experience no intermolecular attractions and these forces cause the gas to deviate from ideal behavior.

B. At very low temperatures, gas particles move slowly.

C. At very high pressures, gas particles are very close together.

Got it right on edge :)

Explanation:

this question tion is so hard sorry but I can't do is sorry

Answer:Gained, Lost , Shared

Explanation:

The oxidation state tells you how many electrons an atom has GAINED.................. , LOST....................... , or SHARED........................ , in forming a compound.

Oxidation state is defined as the  the total number of electrons that an atom gains or loses when forming a chemical bond with another atom.

----To form an ionic bond for example in NaCl, Na, with 11 electrons and one valence electron in its outermost shell donates or lose that valence electron to Chlorine  with 17 electron and 7 in its outermost shell. Therefore Sodium, Na acquires the +1 oxidaton state to become stable and Chlorine acquires the -1 oxidation state  to become stable  forming the  NaCl compound.

To form a covalent compound, There must be sharing of electrons between atoms.For example, in PCl3,  The  phosphorous atom with atomic number 15 shares its three unpaired electrons with the single valence electrons of three chlorine atoms. making the four molecules to attain stability with  Phosphorous having +3 and the chlorine atoms having -1 oxidation states

Answer:

D . A substance with a pH of 8

Explanation:

pH stands for "Potential for Hydrogen." This is an indicator of a solution's acidity or alkalinity. It is also used to tell which chemicals are great for cleaning.

pH 7 and pH 8 are both considered "neutral pH," thus, solutions with these pH are often used as dishwashing detergents because they do not destroy the surfaces of objects. However, pH 8 is said to be more alkaline in nature. This allows it to destroy the residues, such as fats and oils, in pots and pans. It is the pH of baking soda.

Answer:

The answer is D

I searched it up to verify.

Answer: I think the possible answer is B or D

Explanation: There are few of the energies like: Gravitational, electrical, Chemical.....

Answer:

68.6 °C

Explanation:

From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'

Q = Q'

Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g

Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown

So, mL = m'c(θ₂ - θ₁)

θ₂ - θ₁ = mL/m'c

θ₂ = mL/m'c + θ₁

substituting the values of the variables into the equation, we have

θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C

θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C

θ₂ = 43.56 °C + 25 °C

θ₂ = 68.56 °C

θ₂ ≅ 68.6 °C

So, the final temperature (in °C) of the metal block is 68.6 °C.

The final temperature of the metal block is 74.97°C

The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.

From the parameters given:

The number of moles of acetone is:

[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]

= 0.0573 mol

At standard conditions, the heat of vaporization of acetone is:

[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]

Given that:

The specific heat of the aluminum is = 0.903 J/g° C

The heat energy can be computed as:

q = msΔT

q = 41 g × 0.903 J/g° C × (x - 25°C)

Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.

i.e.

[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]

[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]

[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]

[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]

x = 74.97 °C

Learn more about specific heat here:

https://brainly.com/question/1430612

Answer:

Nitrogen and Oxygen make up 99% of the Earths atmosphere. Then Argon makes up the rest of the atmosphere.

Answer:

Scientific Method.

Explanation:

A scientific method is basically a method or a process when you conduct an experiment. Normally, the process goes like this:

1. You make like a question or something that you want to investigate, it's like the aim of the experiment.

2. You make an experiment and a hypothesis. A hypothesis is basically a guess on how the results of the experiment would turn out. You don't have to be correct for the hypothesis since there is no right or wrong answer.

3. Conduct the experiment. I don't think this needs a detailed explanation since experiments vary from one another.

4. Collect results. The data you collect come in different ways based on your experiment, but it is crucial you get data so that you can answer your question in 1.

5. Make inferences. You can't directly get a conclusion or answer from the results, so inferences are needed.

6. Craft a conclusion or answer. This is the final step when conducting an experiment and the part where you have the answer you needed when you conducted the experiment :)

Answer:

A

Explanation:

A Equations showing which elements are oxidized and which are

Answer:

A.

Explanation:

Equations showing which elements are oxidized and which are

reduced

Explanation: cirrocumulus

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

Answer:

Lithium sulphate (Li₂SO₄) and water (H₂O

Explanation:

H₂SO₄ + 2LiOH —> Li₂SO₄ + 2H₂O

The equation represented above indicates a neutralization reaction.

A neutralization reaction is a reaction involving acid and base which result in the production of salt and water.

In the equation above,

Reactant:

H₂SO₄ (acid)

LiOH (base)

Product:

Li₂SO₄ (salt)

H₂O (water)

Thus, lithium sulphate (Li₂SO₄) and water (H₂O) are the products of the reaction

Answer:

18.3%

Explanation:

Add the numbers together, and then take the number of grams of the substance, in this case copper, not coppper lol. divide the .45 by 2.45 to get 18.3

Answer:

C.  physical

Explanation:

A mixture is a physical combination. Mixtures are combinations of compounds and molecules without any chemical reaction taking place.

Mixtures have the following properties:

Answer:

15 m/min

Explanation:

You take the 1500 divide by 10 and your answer is 15

Answer:

0.967mole

Explanation:

Given parameters:

Volume of NH₄Cl  = 21.67L

Unknown:

Number of moles  = ?

Solution:

If we assume that the volume was taken at standard temperature and pressure,

 Then;

  Number of moles  = [tex]\frac{volume }{22.4L}[/tex]  

 Number of moles  = [tex]\frac{21.67}{22.4}[/tex]   = 0.967mole