Atomic number is equal to the number of electrons in an atom?.

Answer:

the volume will expand

Explanation:

gas under pressure contracts, and expands with a lesser pressure

The volume of the hydrogen gas at 25 kPa is 8 Liters.

Explanation:

Given:

At constant temperature, 2 liters of hydrogen gas at 100kPa pressure.

To find:

The volume of the hydrogen gas at 25kPa.

Solution:

The initial pressure of the hydrogen gas =[tex]P_1=100 kPa[/tex]

The initial volume of the hydrogen gas at 100 kPa =[tex]V_1=2 L[/tex]

The final pressure of the hydrogen gas =[tex]P_2=25 kPa[/tex]

The final volume of the hydrogen gas at 25kPa = [tex]V_2=?[/tex]

Using Boyles law:

[tex]P_1V_1=P_2V_2\\100kPa\times 2 L=25 kPa\times V_2\\V_2=\frac{100 kPa\times 2L}{25 kPa}=8L[/tex]

The volume of the hydrogen gas at 25 kPa is 8 Liters.

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Answer:

V = 34.55 L

Explanation:

Given that,

No of moles, n = 1.4

Temperature, T = 20°C = 20 + 273 = 293 K

Pressure, P = 0.974 atm

We need to find the volume of the gas. It can be calculated using Ideal gas equation which is :

PV=nRT

R is gas constant, [tex]R=0.08206\ L-atm/mol-K[/tex]

Finding for V,

[tex]V=\dfrac{nRT}{P}\\\\V=\dfrac{1.4\times 0.08206\times 293}{0.974 }\\\\V=34.55\ L[/tex]

So, the volume of the gas is 34.55 L.

✅Paraphrasing and summarizing .✅

IamSugarBee

Answer:

Love it because Love it

Explanation:

Answer: Yes.

Explanation:

the number of protons in the nucleus determines an element's identity. Chemical changes do not affect the nucleus, so chemical changes cannot change one type of atom into another. The number of protons in a nucleus does change sometimes, however. The identity of the atom, therefore, changes.

Answer:

1.1 x [tex]10^{9}[/tex] km/h

Explanation:

Here we need to do two conversions- one from centimetres to kilometres and one from seconds to hours.

To get from cm to km- we divide by 100 000 since there are 100 000 cm in a km.

To get from seconds to hours we divide by 3600 since there are 3600 seconds in an hour

[tex]\frac{3*10^{10}cm/100000 }{1second/3600} =1.1*10^{9} km/h[/tex]

Answer:

.

Answer: 5 All of the molecules have the same kinetic energy

since the temperature is kept constant at 298 K

Explanation:

The AVERAGE kinetic energy is directly proportional to the absolute temperature.

All the molecules have the same average kinetic energy as average kinetic energy is directly proportional to the absolute temperature. So, the correct option is 5.

The average kinetic energy (K) is equal to one-half of the mass (m) of each gas molecule times the root mean square speed (Vrms) squared.

We know that the average kinetic energy is directly proportional to the absolute temperature.

All of the molecules have the same kinetic energy since the temperature is kept constant at 298 K.

Therefore, All the molecules have the same average kinetic energy as average kinetic energy is directly proportional to the absolute temperature.

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Answer:

2Mg+[tex]O_{2}[/tex]→2MgO

Explanation:

The first step is magnesium + oxygen equals magnesium oxide

The second step is changing that into an equation which looks like Mg+[tex]O_{2}[/tex]→MgO

The third step is to 2*Mg and 2*O as well as the product has to be 2*Mg,2*O which gets the equation to become balanced as 2Mg+[tex]O_{2}[/tex]→2MgO

The coefficient 2 balance the given reaction. The balanced equation for the given reaction is given as [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].

A balanced equation is a mathematical representation of a chemical reaction that respects the law of mass conservation. It depicts the reactants and products of the reaction, as well as the relative amounts of each species. The unbalanced equation is [tex]\rm Mg + O_2 \rightarrow MgO[/tex]. One magnesium (Mg) atom on the left side and one on the right side, so the magnesium is already balanced. Balance the oxygen (O) atoms. On the left side, there are two oxygen (O) atoms present in the O2 molecule. On the right side, there is only one oxygen (O) atom in the MgO molecule. To balance the oxygen atoms, we need to add a coefficient of 2 in front of MgO: [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex]. The balanced equation is [tex]\rm Mg + O_2 \rightarrow 2MgO[/tex].

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Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

So we have

[tex]density = \frac{25}{90} = \frac{5}{18} \\ = 0.277777...[/tex]

We have the final answer as

Hope this helps you

Answer:

D. Limitations due to ethical concerns about experimental subjects.

Explanation:

Answer:

A

Explanation:

(its my friend)

Answer:

C

Explanation:

the rest arent scientific

Answer:

C. Investigations

Explanation:

Test approved

Answer:

36%

Explanation:

This is the answer on edmentum/plato. Hope this helps. Jesus loves YOU!

The density of the wood : 1.45 g/cm³

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density  

The unit of density can be expressed in g/cm³ or kg/m³  

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume  

[tex]\tt V=2.7\times 5.5\times 3.9=57.915~cm^3[/tex]

[tex]\tt \rho=\dfrac{m}{V}\\\\\rho=\dfrac{84~g}{57.915~cm^3}=\boxed{\bold{1.45`g/cm^3}}[/tex]

Answer:

T₂ =  344.8 K

Explanation:

Given data:

Initial volume of gas = 475 cm³

Initial temperature = 273 K

Final volume = 600 cm³

Final temperature = ?

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₂ = T₁V₂/V₁  

T₂ = 273 K × 600 cm³ /  475 cm³

T₂ = 163800K . cm³ / 475 cm³

T₂ =  344.8 K

Answer:

easier and pollution

Explanation:

I just had this question and got it right

Answer:

it's the first one

Explanation:

can you help me too

Answer:

Salt

Explanation:

It has all -

Alkanes are saturated hydrocarbons that have single bonds in chains

General formula for alkanes :

[tex]\tt \large{\bold{C_nH_{2n+2}}[/tex]

Hydrocarbon combustion reactions (specifically alkanes)

[tex]\large {\box {\bold{C_nH _ (_2_n _ + _ 2_) + \dfrac {3n + 1} {2} O_2 \Rightarrow nCO_2 + (n + 1) H_2O}}}[/tex]

So that the burning of ethane with air (oxygen):

[tex]\tt C_2H_6+\dfrac{7}{2}O_2\rightarrow 2CO_2+3H_2O[/tex]

2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)

or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction

C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)

C : left 2, right b ⇒ b=2

H: left 6, right 2c⇒ 2c=6⇒ c= 3

O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2

Answer:

4.8 x 10^1

Explanation:

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10. If the decimal is being moved t the right, exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 30.5 g

volume = 2.2 cm³

We have

[tex]density = \frac{30.5}{2.2} \\ = 13.863...[/tex]

We have the final answer as

Hope this helps you

Answer: 2miles

Explanation:if he’s going 12 miles in one hour, in half an hour he would’ve made it 6 miles. 8-6=2

Answer: b. 2 miles

Explanation:

Answer:

The block is made up of aluminum.

density = 2.7 g/cm³

Explanation:

Given data:

Dimension of metal block = 2.0 cm×2.5 cm× 3.0 cm

Mass of block = 40.05 g

Density of block = ?

Which metal is this = ?

Solution:

Density:

Density is equal to the mass of substance divided by its volume.

The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.

Units:

SI unit of density is Kg/m3.

Other units are given below,

g/cm3, g/mL , kg/L

Formula:

D=m/v

D= density

m=mass

V=volume

Volume of block = 2.0 cm×2.5 cm× 3.0 cm = 15 cm³

d = m/v

d = 40.5 g/ 15 cm³

d = 2.7 g/cm³

The block is made up of aluminum.

Answer:

Photic Zone

Explanation:

The photic zone is the uppermost layer of the sea that recieves sunlight allowing phytoplankton to perform photosynthesis.

Answer:

This is a synthesis reaction.

Explanation:

Two elements are bonded together to form (synthesize) a new compound.

Answer:

See explanation

Explanation:

The question is incomplete because the image of the alcohol is missing. However, I will try give you a general picture of the reaction known as hydroboration of alkenes.

This reaction occurs in two steps. In the first step, -BH2 and H add to the same face of the double bond (syn addition).

In the second step, alkaline hydrogen peroxide is added and the alcohol is formed.

Note that the BH2 and H adds to the two atoms of the double bond. The final product of the reaction appears as if water was added to the original alkene following an anti-Markovnikov mechanism.

Steric hindrance is known to play a major role in this reaction as good yield of the anti-Markovnikov like product is obtained with alkenes having one of the carbon atoms of the double bond significantly hindered.

Answer:

1. Both metals and nonmetals are types of elements and can be involved in chemical reactions. Some of their differences are highlighted in the chart below.

  Metals:    

Appearance; Shiny.    

Conduct heat or electricity; Yes.  

Malleable or ductile; Yes, both and has great mechanical strength.    

Form stable compounds; Forms stable compounds with acids; also forms oxides; replaces hydrogen in acids or water; combine with nonmetals; often becomes positive.

  Nonmetals :  

Appearance; Not shiny .  

Conduct heat or electricity; Not well .  

Malleable or ductile; Brittle and not easily molded into shapes .  

Form stable compounds; Oxides usually give acid reactions in water; often becomes negative

2. The electrochemical series is an arrangement of metals in such order that any metal in the list is displaced from its compounds by any metal above it, but displaces any metal below it. The higher up the list a metal is, the greater its activity. Knowing a metal’s placement on this chart can help you understand the activity of the metal, especially in regard to its ability to displace hydrogen in acids. Any items on the list far above hydrogen will do a good job at displacing it, those near it won’t do such a good job, and those below it won’t displace it from acids at all.

3. When placed in water, acids dissociate and form free hydrogen ions, which determine the properties of acids. The number of hydrogen ions determines the strength of an acid. Strong acids dissociate to a large degree and produce a large number of hydrogen ions. Weak acids dissociate to only a slight degree.

When placed in water, bases dissociate and form free hydroxyl ions, which determine the properties of bases. Strong bases dissociate to a great degree and produce a large number of hydroxyl ions. Weak bases dissociate to only a slight degree.

When free hydrogen ions and free hydroxyl ions are removed from solutions of acids and bases, then the acidic and basic properties disappear. This is what happens when acids and bases are mixed together in proper proportion; the hydroxyl ion will unite with the hydrogen ion to form water. The resulting salt product is neutral.

4. Indicators are used to help determine the pH value of an unknown solution. These are often papers that turn a certain color at certain pH values.

Metals are good conductors of heat and electricity but the non-metals are not.

Metals are good conductors of electricity and heat whereas non-metals are poor conductors of heat and electricity. Metals have high density while on the other hand, non-metals have low density. Metals are malleable and ductile whereas non-metals are brittle.

So we can conclude that metals are good conductors of heat and electricity but the non-metals are not.

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Answer:

A. Potential energy is stored energy

Explanation:

Answer:

A

Explanation:

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