Jacinta wrote the following passage about chemical changes.

A chemical change is a change that results in one or more new substances with different properties. When a chemical change occurs, the new substance can give off an odor, such as rotting fruit or cookies baking in the oven. Chemical changes can cause color changes, such as iron rusting and turning a reddish-brown color. When wood is burned or ingredients are mixed for baking a cake, a new substance is made.

Choose the best statement that Jacinta can add to her passage.

Chemical changes, such as rotting fruit and burning wood, are affected by temperature. More heat and energy causes a faster chemical change.
Wood burning and fruit rotting creates new substances through a chemical change that is affected by sound energy.
Rotting fruit and burning wood is a chemical change that occurs because there is a decrease in temperature. Less heat causes a faster chemical change.
When a chemical change occurs, the new substance that is created has properties similar to the original substance.

Answer:

P¹V¹/T¹=P²V²/T² here

P²= 1.25- atm

V²=?

T²=345K

P¹=0.75-atm

V¹=120

T¹=295K

So V²= (0.75 x120/295)x(345/1.25)

Volume of the gas V²= 84.20- ml

Answer:

Solution given:

at first

volume[tex]V_{1}=120.0ml[/tex]

pressure [tex]P_{1}=0.75atm[/tex]

temperature [tex]T_{1}=22+273=295°K[/tex]

after increasing temperature and pressure

volume[tex]V_{2}=xml[/tex]

pressure [tex]P_{2}=1.25atm[/tex]

temperature [tex]T_{2}=70+273=343°K[/tex]

now

[tex]\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}[/tex]

substituting value

[tex]\frac{0.75*120}{295}=\frac{1.25*x}{343}[/tex]

0.305=5x/1372

Doing criss cross multiplication

5x=0.305*1372

x=418.46/5

x=83.69ml

x=84ml

the volume will be 84ml

Answer:

1 . statement is false

2. statement is true

Answer:

Explanation:

As per being a Group 7 element, it would gain one electron, which changes it's charge to 1-. It is therefore negatively charged, having a full outer shell of 8, having its electronic structure to be at 2,8,8.

Answer:

Zn²⁺ + 2Ag → Zn + 2Ag⁺

Explanation:

According to the reduction potential chart, silver ion (Ag⁺) is a stronger oxidizing agent than zinc (Zn), which is a reducing agent the compared to silver

Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series

The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76

The reduction potential for Ag⁺ + e⁻ → Ag = +0.8

Given that redox reactions are reversible, we get the following likely redux reaction:

Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)

Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.

Answer:

process of depositing a thin layer of any superior metal over an object of a cheaper metal, with the help of electric current

Explanation:

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Answer:

K = [N2] [Cl2]³ / [NCl3]²

Explanation:

The equilibrium expression, K, of a reaction:

aA + bB ⇄ cC + dD

Is defined as the ratio between the multiplication of concentrations of products powered to its reaction coefficient and the multiplication of concentrations of reactants powered to its reaction coefficient as follows:

K = [C]^c[D]^d / [A]^a[B]^b

Now, for the reaciton:

2NCl3 ⇄ N2(g) + 3Cl2(g)

K is:

K = [N2] [Cl2]³ / [NCl3]²

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Answer:

The composition of air can be determined by an experiment which includes passing a known volume of air, measured at a known temperature and pressure, over sufficient amount heated copper granules/powder, and measuring the volume gas remaining after the gas cools down to the temperature at which the first measurement was taken

Oxygen reacts with copper according to the following chemical reaction

2Cu (s) + O₂ (g) → 2CuO (s)

Cupper does not react with the other constituents of air

Whereby the initial volume of air was 100 cm³, we have;

Percentage of oxygen in air = 100 - The final volume reading of the container initially holding the air

When done using am appropriate experimental setup, the percentage of gases remaining equals 79% to 80%, therefore, the percentage composition of oxygen in air is between 20 and 21 percent

Explanation:

Answer:

C. Molecules

Explanation: Water is a compound that conatins molecules hydrogen and oxygen.

Answer: Atoms

Explanation:

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Answer:

The lighting filters use subtractive properties to bring light of a color to the eye because subtractive color mixing uses white light source with a series of filter to eliminate certain wavelengths of light.

Different colour lights (RBG) uses additive properties to bring light of a certain color to our eyes.

Color synthesis is the art of forming different types of colours from small number of primary colours. The color formed is called a secondary color.

Color synthesis is carried out through the following means:

In additive color synthesis, the three primary colours lights that are combined is Red(R), Blue (B) and Green(G).

The wavelength from the various color light combine to generate white light which is visible to the eye.

Therefore, different colour lights (Red, Blue and Green) uses additive properties to bring light of a certain color(white) to our eyes.

Learn more about color synthesis here:

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Explanation:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

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Answer:

Check Down

Explanation:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bond.

Answer:

Explanation:

Element -

It is the basic unit of matter, which cannot be broken down into substances by any way but can be combined to form new substances.

It is a pure substance.

It classifies into metals, non-metals, metalloids and noble gases.

Example - Hydrogen, Carbon, Oxygen

Compounds -

It is a combination of two or more elements.

It is a pure substance.

Through chemical reactions, they can be broken down into metals.

Example - Water, Carbon dioxide

Mixtures -

It is a combination of two or more elements or compounds or both.

The substances combined in a mixture are in a particular ratio.

Example - Chalk powder, Washing Soda

Answer:

A Calorimeter is a device used to measure the amount of heat involved in a chemical or physical process.

Explanation:

Ex- when an exothermic reaction ( accompanied by or requiring absorption of heat)occurs in solution in a calorimeter, the heat produced by the reaction is absorbed by the solution increasing its temperature.

   - When an endothermic reaction (Heat evolving reaction) occurs, the heat required is absorbed from the thermal energy of the solution, decreasing its temperature.

A burning piece of coal which is releasing heat due to its combustion and is transferred to water.

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Answer: A reaction element are those elements that can take part in a chemical reaction.

Explanation:

An element is made up of atoms that has the same atomic number. It is the basic material of which all matter is composed of. These elements cannot be broken down further into smaller substances by any chemical reaction. Each element has a unique number of protons in its atom. For example,

--> a hydrogen atom has 1 proton,

--> a Helium atom has 2 protons,

--> a Lithium atom has 3 protons, and

--> a carbon atom has 6 protons.

A chemical reaction on the other hand involves rearrangement of the constituent atoms of reactants to create different substances as products. The bonds between atoms are either broken or created to form new molecules. There are different types of chemical reaction which includes:

--> Decomposition reaction

--> Neutralization reaction

--> single displacement reaction and

--> combustion reaction.

Answer:

0 K

[tex]{ - \bf{273 \degree C}}[/tex]

298 K

[tex]{ \tt{ = 298 - 273}} \\ = { \bf{25 \degree C }}[/tex]

323 K

[tex]{ \tt{ = 323 - 273}} \\ = { \bf{50 \degree C}}[/tex]

423 K

[tex]{ \tt{ = 423 - 273}} \\ = { \bf{150 \degree C}}[/tex]

1.T=[£+273]

=273

It is because kelvin temperature is absolute zero.

Explanation:

your answer was correct

Answer:

[tex]{ \bf{2P _{(s)} + 5Cl _{2(g)} → 2PCl _{5(s)}}}[/tex]

▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓

[tex]\boxed{\pmb{\purple{\sf{2P(s) + 5Cl _{2}(g)\dashrightarrow 2PCl _{5}(s)}}}}[/tex]

▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓

Answer:

depends on the element it's reacting with..

Explanation:

if the another element requires less energy to loose electron then zinc will become negatively charged and hence becomes acidic radical..

normally if it is reacting with element with valency 4 and Atomic number less than it(Ti,Si,C) then it will lose electron and gain positive sign and henve becomes basic radical..

Explanation:

because there are 4 Iodines on the left, we'll put. 4 in front of NaI to balance it. This would result in 4 Na on the left, so we'll put a 2 in front of Sodium Sulfate to balance the right side. Now we have 4 Na and I on both side, as well as 2 Sulfate on both sides. Pb is already balanced. The equation is now complete.

Answer: the extent of dissociation of the acid or base

Explanation:

When an acid or base dissociates, it means that they go back to their original ions in order to be able to react with the atoms in the solution they dissociated in.

Stronger acids and bases are able to almost completely dissociate in a solution which is why they are able to react with the atoms in the solution very easily. The strength of an acid or base is therefore measured by how much dissociation they can manage in a solution.

Answer:

i know you think that they are just related because kg has kilo but they are related because

Explanation:

1000g makes 1 g.You see how much there is a difference in the solution because how is one=one thousand,well that is all i can help you from here.bye panta

Answer:

1 g=1000kg

Explanation:

They are related in mathematical way

The option which isn't a result of surface tension in water is: c. surface area is maximized.

Water can be defined as a liquid molecule that comprises the chemical element hydrogen and oxygen in the ratio of two to one (2:1).

Surface tension can be defined as a property of liquid such as water, which makes its surface to resist an external force due to the cohesive nature of its molecules.

This ultimately implies that, the surface tension of a liquid is mainly as a result of the cohesive forces existing between its molecules.

Generally, the surface tension of water is typically higher than the surface tension of most liquids.

Due to the effect of surface tension in water;

Additionally, the surface tension of a liquid such as water can be described as an inward force which tends to minimize its surface area rather than maximize its surface area.

In conclusion, surface tension in water doesn't maximize its surface area.

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Answer:

[tex]\boxed {\boxed {\sf A. \ 186.94 \ L}}[/tex]

Explanation:

We are asked to find the original volume of a gas given a change in temperature. Since pressure remains constant, we are only concerned with volume and temperature, so we use Charles's Law. This states the volume of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]

The gas begins with a temperature of 450 Kelvin, but the volume is unknown.

[tex]\frac {V_1}{450 \ K }= \frac{V_2}{T_2}[/tex]

The gas is cooled to 248.9 Kelvin and the gas occupies a volume of 103.4 liters.

[tex]\frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}[/tex]

Since we are solving for the original volume, we must isolate the variable V₁. It is being divided by 450 Kelvin. The inverse operation of division is multiplication, so we multiply both sides of the equation by 450 K.

[tex]450 \ K \frac {V_1}{450 \ K }= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]

[tex]V_1= \frac{103.4 \ L}{248.9 \ K}* 450 \ K[/tex]

The units of Kelvin cancel.

[tex]V_1= \frac{103.4 \ L}{248.9 }* 450[/tex]

[tex]V_1= 0.4154278827 \ L *450[/tex]

[tex]V_1= 186.9425472 \ L[/tex]

Round to the nearest hundredth. The 2 in the thousandths place tells us to leave the 4 in the hundredth place.

[tex]V_1 \approx 186.94 \ L[/tex]

The original volume is approximately 186.94 liters and Choice A is correct.

Answer:

they are weak forces that attract neutral molecules to one another

Explanation:

particles in liquid or air vibrate and move constantly thus they collide