Please Help me with number 4 I really need help please just tell me which letter is

Answer:

the main use of coal in the United States is to generate electricity.

Coal is a combustible black or brownish-black sedimentary rock with a high amount of carbon and hydrocarbons

Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.

Answer:

2L of nitrogen gas will be needed

Explanation:

Based on the following reaction:

N₂ + 3H₂ → 2NH₃

1 mole of nitrogen reacts with 3 moles of hydrogen to produce 2 moles of ammonia.

If 6L of hydrogen (In a gas, the volume is directly proportional to the moles, Avogadro's law) react, the volume of nitrogen gas required will be:

6L H₂ * (1mol N₂ / 3 moles H₂) =

Explanation:

Homogeneous catalysts are those that occupy the same phase as the reaction mixture (typically liquid or gas), while heterogeneous catalysts occupy a different phase. Generally, heterogeneous catalysts are solid compounds that are added to liquid or gas reaction mixtures.

Answer:

56.94759 grams of NO2

Explanation:

Stoichiometric Equation:

1 S + 6 HNO3 → 1 H2SO4 + 6 NO2 + 2 H2O.

This is so you can create ratios between each compound in the reaction, and identify the limiting and excess reactants to determine exactly how much can be produced?

The coefficients or molecular quantity of each compound in the balanced equation represents the amount of moles.

To figure out how much can be produced, you have to convert 59.54 g of S into moles of S and 78 g of HNO3 into moles of HNO3.

A reference such as a periodic table can be very helpful as it has the atomic mass of each element which is the mass with respect to 1 mol of that element.

Answer:

Solids, liquids, gases - all matter - are made up of atoms (or other things, like molecules, that are made from atoms)! ELEMENTS are the kinds of atoms that we can have. Carbon is an element, hydrogen is an element, and so is oxygen. ... Atoms can join together - they form bonds together - to make MOLECULES.

Answer:

See Explanation

Explanation:

10) From the options provided for this question, gamma particle is the most energetic. Recall that gamma rays are high energy electromagnetic radiation which are capable of causing a high degree of ionization in matter.

11) The bombardment of U-235 with neutrons leads to the reaction;

[tex]U\frac{235}{92} + n\frac{1}{0}---> I\frac{138}{53} + Y\frac{95}{39} +3n \frac{1}{0}[/tex]

Hence

a = 92, b= 95, c= 53

12) In positron emission, a proton is transformed into a neutron. The mass number of the daughter nucleus is the same as its parent but the atomic number decreases by 1.

Hence;

[tex]Th\frac{231}{90} -----> e\frac{1}{0} +Ac \frac{231}{89}[/tex]

Answer:

solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and soil. As liquid water evaporates or transpires, it forms water vapor and clouds, where water droplets eventually gain enough mass to fall back to Earth as precipitation.

Answer:

Oxidation - reduction reaction which is called redox reaction.

Explanation:

The type of reaction that is a part of another type but treated separately is called Oxidation - reduction reaction.

Thus is because they usually involve 2 separate half reactions which are oxidation reactions that involve loss of electrons and then reduction equations which involve gain of electrons.

They are treated separately for example when sodium reacts with chlorine to form sodium chloride.

2Na + Cl2 = 2NaCl

Now, sodium undergoes oxidation by loosing elctrons and it's half reaction is;

2Na → 2Na​^(+) + 2e^(-)

​​Meanwhile chlorine undergoes reduction by gaining electrons and its half reaction is;

Cl2 + 2e^(-) → 2Cl^(-)

Answer:

cool

Explanation:

6:c

7: might be ice but im not really sure, hope you do well.

Explanation:

Answer:

75m

Explanation:

To prepare 267 mL of  0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.

We need to prepare the solution of 0.25 M NaCl using 1.75 M NaCl solution, we can use the dilution formula:

[tex]C_1V_1 = C_2V_2[/tex]

where [tex]C_1[/tex], [tex]V_1[/tex] is the concentration and the volume of the initial solution, [tex]C_2[/tex], [tex]V_2[/tex] is the concentration and the volume of the final solution.

We know the final concentration and the final volume that we are required to make. So we can use the above relation to find  [tex]V_1[/tex] of the solution:

[tex]V_1 = (C_2 * V_2) / C_1[/tex]

Now after substituting the values in the relation, we get:

[tex]V_1 = (0.25 M x 267 mL) / 1.75 M\\V_1 = 0.03829 L or 38.29 mL[/tex]

So to prepare 267 mL of  0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.

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Answer:6.0g x 1 mol/18.02g x 40,65 kJ/mol

Explanation: just did the quiz

13.6 kilojoules (kJ) of energy is released when 6.0 g of water is condensed from water to vapor.

To calculate the energy released when 6.0 grams of water is condensed from water to vapor, we need to use the concept of heat of vaporization (also known as enthalpy of vaporization). The heat of vaporization is the amount of energy required to change one gram of a liquid into vapor at its boiling point, without any change in temperature.

The heat of vaporization of water is approximately 40.7 kJ/mol at its boiling point (100°C or 373.15 K). We can use this information to calculate the energy released when 6.0 grams of water is condensed.

Step 1: Calculate the number of moles of water (H₂O) in 6.0 grams.

Molar mass of water (H₂O) = 2 g/mol (for hydrogen) + 16 g/mol (for oxygen) = 18 g/mol

Number of moles of water = Mass of water / Molar mass of water

Number of moles of water = 6.0 g / 18 g/mol = 0.333 moles

Step 2: Calculate the energy released during condensation.

Energy released = Number of moles of water × Heat of vaporization

Energy released = 0.333 moles × 40.7 kJ/mol = 13.6 kJ

Therefore, approximately 13.6 kilojoules (kJ) of energy are released when 6.0 grams of water is condensed from water to vapor.

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Answer:

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

Explanation:

Explanation:

As you can that water splits into molecules of hydrogen and 1 molecules of oxygen since , number of molecules of hydrogen released is double the number of molecules of oxygen released, volume occupied by hydrogen gas is double the volume occupied by oxygen gas

Answer:

The amount of HI is "64 grams".

Explanation:

The given values are:

Volume,

= 0.500 L

Molarity,

= 1.00 H

Molar mass of HI,

= 128

Now,

The moles of HI will be:

=  [tex]Molarity\times Volume[/tex]

On substituting the values, we get

=  [tex]1.00\times 0.500[/tex]

=  [tex]0.5 \ mol[/tex]

hence,

The amount of HI will be:

=  [tex]Moles\times Molar \ mass[/tex]

=  [tex]0.5\times 128[/tex]

=  [tex]64 \ grams[/tex]

Answer:

si. en los atomos los protones y los electrones llevan cargas electricas

Answer: 2M + 3Q2 -----> 2MQ3

Explanation:

2 Ms either side, and 6 Qs either side

Answer:

[tex]a=-3.37\ m/s^2[/tex]

Explanation:

Given that,

A car accelerates negatively from 35m/s to 8m/s in 8s.

We need to find the car's acceleration.

Initial speed, u = 35 m/s

Final speed, v = 8 m/s

Time, t = 8 s

The acceleration of an object is equal to the rate of change of velocity. So,

[tex]a=\dfrac{v-u}{t}[/tex]

Put all the values,

[tex]a=\dfrac{8-35}{8}\\\\a=-3.37\ m/s^2[/tex]

So, the acceleration of the car is equal to [tex]-3.37\ m/s^2[/tex].

Answer:

24.2 mL.

Explanation:

Assuming constant temperature, we can solve this problem using Boyle's law, which states:

Where:

We input the data:

And solve for V₂:

The closest option is the second one: 24.2 mL.

Answer:

cardiac

Explanation:

Answer:

true

Explanation:

drought is a period of unusually persistent dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages. The severity of the drought depends upon the degree of moisture deficiency, the duration, and the size of the affected area.

The statement " It has two carbon-carbon double bonds" is correct. because Q is a kind of unsaturated hydrocarbon.

What is unsaturated hydrocarbon?

The type of compound which contain double bond or triple bond can be considered as unsaturated hydrocarbon. Unsaturated hydrocarbon can decolorized bromine water.

Two kinds of unsaturated hydrocarbon will obtain, alkene and alkyne.

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Answer:

A: catalyst

Explanation:

In Chemistry, the rate of reaction of chemical elements (reactants) can be sped to produce a chemical compound or elements (products), through the addition of a catalyst that is unaffected by the reaction.

This ultimately implies that, to speed up a chemical reaction, add a catalyst that is unaffected by a reaction.

For example, an enzyme refers to a biological catalyst that is typically used to speed up (accelerate) the rate of a chemical reaction by lowering the activation energy of its reactants.

An enzyme can be defined as a biological catalyst that typically lowers the activation energy of a biological reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy.

Generally, an increase in temperature increases or speeds up the rate of a reaction while low temperature limits or reduces the rate of a reaction. The optimal temperature for enzymes in the human body is around 37 degrees celsius.

Answer:

1 and 3

Explanation:

oh this one lol,, hope it helps

Answer:

1 and 3

Explanation:

hope this helps :)

Answer:

Five ( 5 ) is the correct answer

Answer:

mass = 17.2 grams

Explanation:

q = mcΔT => m = q/cΔT = 187j / (0.90j/g°C)(35.6°C - 23.5°C) = 17.2g