How many atoms of Carbon are found on the PRODUCTS side?

Answer:

Hypothesis: IF a penny is dropped from a building, THEN it would kill a pedestrian below

Controls: Same building, Same distance

Independent variable: Penny

Dependent variable: Pedestrian's death

Conclusion: The hypothesis is rejected

Explanation:

- The hypothesis is a testable explanation to an observed problem or asked question. Based on the cientific question in this question, a possible hypothesis will be: IF a penny is dropped from a building, THEN it would kill a pedestrian below

- Independent variable is the variable that is changed or manipulated in an experiment. In this case, the PENNY is the independent variable

- Dependent variable is the variable that responds to the change made to the independent variable. It is the measured variable. In this case, the dependent variable is the DEATH OF PEDESTRIANS.

- Controls are those variables that is kept constant or unchanged throughout the experiment. The controls in this experiment are: Same building, Same distance of throw etc.

- The conclusion is whether the hypothesis is accepted or not depending on the result of the experiment conducted. In this case, the hypothesis will be rejected if the penny doesn't kill a pedestrian

Answer:

Explanation:

Al(s) + 3/2 Br₂(l) = AlBr₃(s)

K = [  AlBr₃] / [ Al] [  Br₂]³/²

K² =  [  AlBr₃]² / [  Al ] ² [ Br₂]³

2 AlBr₃ = 2 Al(s) + 3 Br₂(l) =

K₁ =  [  Al ] ² [ Br₂]³ /  [  AlBr₃]²

K₁ =  ( 1 / K² ) = K⁻²

2 ) 2 Al(s) + 3 Br₂(l) = 2 AlBr₃(s)

K₂ = [ AlBr₃ ]² / [  Al ]² [  Br₂ ]³

K₂ = K²

3 )

AlBr₃(s) =   Al(s) + 3/2 Br₂(l)

K₃  = [ Al ] [ Br₂ ] ³/² / [ AlBr₃ ]

=  ( 1 / K ) = K⁻¹

Answer:

2.35 x 10²⁰ atoms Ga

Explanation:

After converting from mg to g, use the molar mass as the unit converter to convert to moles. Then using Avogadro's number, 6.022 x 10²³ convert from moles to atoms of Ga.

[tex]27.2mgGa*\frac{1g}{1000mg} *\frac{1 mol Ga}{69.72gGa} *\frac{6.022*10^2^3 atoms Ga}{1 molGa} = 2.349 * 10^2^0 atoms Ga[/tex]

Then round to 3 significant figures = 2.35 x 10²⁰ atoms Ga.

The number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms

From the question, we are to calculate the number of atoms in a 27.2 mg sample of Ga.

First, we will determine the number of moles of Ga present

Using the formula,

[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass} [/tex]

Mass = 27.2 mg = 0.0272 g

Molar mass = 69.72 g/mol

Then,

[tex]Number\ of\ moles \ of\ Ga = \frac{0.0272}{69.72} [/tex]

[tex]Number\ of\ moles \ of\ Ga = [/tex] 0.000390132 moles

Now, for the number of atoms present

From the formula

Number of atoms = Number of moles × Avogadro's constant

Then,

Number of Ga atoms = 0.000390132 × 6.022×10²³

Number of Ga atoms = 2.35 × 10²⁰ atoms

Hence, the number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms

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Answer:

Potassium chloride, KCl , is an ionic compound formed by the electrostatic force of attraction that holds the potassium cations and the chlorine anions together

Explanation:

Answer:

See explanation

Explanation:

When the temperature was increased, the pressure of the gas in the can was increased.

When Maria removed the can and placed it in cold liquid, the decrease in temperature led to a corresponding decrease in pressure of the gas inside the can hence the can was crushed.

Hypothesis: The pressure of the gas in the can is directly proportional to temperature.

Maria was careless about the experiment. She ought to have first checked whether the hot plate was off before placing the soda can. Secondly,she should not have immediately plunged the soda can into liquid because it will shrink due to decrease in pressure. She should not also have removed the soda can with bare hands to avoid getting burns and blisters.

Answer:

The plant uses carbon dioxide and water to make an entirely new chemical hence chemical change.

Explanation:

Plants create their own 'food', they turn carbon dioxide water and sunlight to create starch and glucose..

Answer:

The properties of carbon dioxide and oxygen are different.

Explanation:

im taking the exam right now and Im pretty sure it's D The properties of carbon dioxide and oxygen are different.

Answer:

5;11

Explanation:

Answer:

2.75 g

Explanation:

The number of moles of KOH is obtained from the equation;

n=CV

C= concentration

V= volume of solution

n= 0.527 × 25.6/1000

n= 0.0135

Reaction equation;

KOH(aq) + KHC8H4O4(aq) --->(KC8H4O4)K(aq) + H2O(l)

1 mole of KHP reacts with 1 mole of KOH

Hence; 0.0135 moles of KHP reacts with 0.0135 moles of KOH

From;

Number of moles = reacting mass/molar mass

Reacting mass = 0.0135 × 204

= 2.75 g of KHP

Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we are finding the new volume

[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]

We have

[tex]V_2 = \frac{300 \times 2}{7} = \frac{600}{7} \\ = 85.714285...[/tex]

We have the final answer as

Hope this helps you

Answer:

You feel warm when you stand near a campfire because the flames of the fire warm your body. The heated waves are hit towards you and your body feels warm.

Hope this helped :)

Explanation:

Answer:

[tex]a=\frac{f}{d-e}-\frac{b}{c}[/tex]

Explanation:

Hello.

In this case, for the equation:

[tex](a+b/c)(d-e)=f[/tex]

For isolating a, we must first pass (d-e) to divide at the other side as it is initially multiplying:

[tex]a+b/c=\frac{f}{(d-e)}[/tex]

Next, as b/c is adding, it passes to subtract at the other side in order to finally isolate a:

[tex]a=\frac{f}{d-e}-\frac{b}{c}[/tex]

Best regards!

Answer:

Kc = 4.86×10⁻⁶

Explanation:

We begin from the equation:

N₂  +  2H₂ ⇄  2NH₃

We start from 3.47×10⁻² moles of N₂(g) and 6.38×10⁻² moles of H₂(g), so when we reach the equilibrium, we get 6.25×10⁻² moles of H₂.

This data means, that in the reaction we made react:

6.38×10⁻² - x = 6.25×10⁻²

x = 1.3×10⁻³ moles of H₂

As stoichiometry is 1:3, we will know that the moles of N₂ that have been reacted were:

1.3×10⁻³ moles / 3 = 4.33×10⁻⁴ moles of N₂

So, in the equilibrium we would have:

3.47×10⁻² moles of N₂ - 4.33×10⁻⁴ moles of N₂ = 0.0343 moles of N₂

How many ammonia, would we have in the equilibrium?

4.33×10⁻⁴ mol . 2 = 8.66×10⁻⁴ moles (from stoichiometry with N₂, 1:2)

(1.3×10⁻³ mol . 2) / 3 = 8.66×10⁻⁴ moles (from stoichiometry with H₂, 2:3)

Let's make the expression for Kc

Kc = [NH₃]³ / [N₂] . [H₂]²

(8.66×10⁻⁴ )³ / (0.0343 . (6.25×10⁻²)² = 4.86×10⁻⁶

Answer:

Percent error

Explanation:

Percent error is defined as the percentage of the difference between the measured( accurate value) and the known value of a substance.

It is usually calculated by:

Measured value — Known value/ known value * 100%

Percent error is the calculated value that is used to evaluate accuracy for a set of data

Answer: The mass of blue copper sulfate is 3.5 g

Explanation:

Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The chemical equation for the heating of copper sulfate crystals is:

Let the mass of blue copper sulfate be 'x' grams

We are given:

Mass of copper sulfate powder = 2.1 grams

Mass of water = 1.4 grams

Total mass on reactant side = x

Total mass on product side = (2.1 + 1.4) g

So, by applying law of conservation of mass, we get:

Hence, the mass of blue copper sulfate is 3.5 grams

Answer:

Ecological islands is just a terminology used, since it isn't surrounded by water like an actual island, instead, it's something isolated from other things, which is the same thing as an island in a way:

Island (geographical) - Land isolated from bigger "main" land masses by water.

Island (ecological) - Land which contains certain isolated features (habitat, plants, etc.).

Explanation:

An ecological island is an area of land, isolated by natural or artificial means from its surrounding land while geographical islands are a body of land surrounded by water.

An ecological island refers to an area of land which is not necessarily an actual island but isolated by natural or artificial means from the surrounding land. A natural micro-habitat exists on sich lands amidst a larger differing ecosystem.

In artificial ecological islands, all non-native species are eradicated, native species are reintroduced and nurtured, and the natural or artificial border is maintained to prevent the reintroduction of non-native species.

A geographical island is a body of land surrounded by water. Continents are also surrounded by water as they are so big but they are not considered islands. Islands may be categorized as either continental or oceanic.

There are so many islands in the lakes, oceans, and rivers around the world. They vary in climate, size, and the types of organisms that inhabit them.

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Answer:

true. cathode rays are deflected

Answer:

NaCl(aq)

Explanation:

Nacl(aq) is an electrolyte when it melts and it conducts electricity. This is due to the fact that when it is in solution, it dissociates to be Na+ and Cl-. These ions are conductors of electricity. It conducts electricity because of the movements and also the discharge of ions. CH3OH(aq) is not a conductor of electricity therefore the first option is the answer.

Answer:

a. 0.183 mol C

b. 0.366 mol H

Explanation:

Assuming total combustion, all of the carbon in the unknown compound turned into carbon dioxide, CO₂.

So first we calculate the CO₂ moles produced, using its molecular weight:

This means in the unknown compound there were 0.183 moles of carbon, C.

Conversely, all of the hydrogen in the unknown compound turned into water, H₂O.

Calculating the H₂O moles:

We multiply the water moles by two, as there are 2 H moles per H₂O mol:

Answer:

2 C 2 H 2 ( g ) + 5 O 2 ( g ) ⟶ 4 C O 2 ( g ) + 2 H 2 O ( l )- combustion reaction

N H 4 N O 3 ( s ) ⟶ N 2 O ( g ) + 2 H 2 O ( l )- decomposition reaction

C O ( g ) + 2 H 2 ( g ) ⟶ C H 3 O H ( l ) - combination reaction

2 F e ( s ) + 6 H C l ( a q ) ⟶ 2 F e C l 3 ( a q ) + 3 H 2 ( g )- Redox reaction

C a C l 2 ( a q ) + N a 2 C O 3 ( a q ) ⟶ 2 N a C l ( a q ) + C a C O 3 ( s )- double displacement reaction

Explanation:

We can determine the type of reaction by considering the reactants and products.

Combustion is a reaction between a substance and oxygen which produces heat and light. The first reaction is the equation for the combustion of ethyne.

A decomposition reaction is one in which a single reactant breaks down to form products. The second reaction is the decomposition of ammonium nitrate.

A  combination reaction is said to occur when two elements or compounds react to form a single product. The third reaction is the combination of carbon dioxide and methane to form  methanol.

An oxidation-reduction reaction is a reaction in which there is a change in oxidation number of species from left to right of the chemical reaction equation. The fourth reaction is the oxidation of iron (0 to +3 state) and reduction of hydrogen (+1 to 0 state).

A double displacement reaction is a reaction in which ions exchange partners from left to right in the reaction equation. The fifth reaction is a double displacement reaction. Both Na^+ and Ca^2+ exchanged partners from left to right of the reaction equation.

Reactions are the formation of the products from the reactant. The types of reactions are combustion, decomposition, combination, Redox and double displacement.

The reaction is a chemical change in the properties of the reactant that forms the products. It can be of various types based on the formation of the product.

The first reaction is combustion as the reactants react and use oxygen to form heat, carbon dioxide and water. The combustion reaction of ethyne can be shown as,

[tex]\rm 2 C _{2} H _{2} ( g ) + 5 O _{2} ( g ) \rightarrow 4 C O _{2} ( g ) + 2 H _{2} O ( l )[/tex]

The second reaction is decomposition in which a single reactant decomposes to form two or more products. The decomposition of ammonium nitrate can be shown as,

[tex]\rm N H _{4} N O _{3} ( s ) \rightarrow N _{2} O ( g ) + 2 H _{2} O ( l )[/tex]

The third reaction is a combination reaction in which two compound or elements combines to form one product. The combination reaction between carbon monoxide and hydrogen to form methanol can be shown as,

[tex]\rm C O ( g ) + 2 H _{2} ( g ) \rightarrow C H _{3} O H ( l )[/tex]

The fourth reaction is redox and includes the oxidation and the reduction of the species of the reaction. In the reaction, iron undergoes oxidation and hydrogen reduction. The redox reaction can be shown as,

[tex]\rm 2 F e ( s ) + 6 H C l ( a q ) \rightarrow 2 F e C l _{3} ( a q ) + 3 H _{2} ( g )[/tex]

The fifth reaction is a double displacement reaction in which the calcium and sodium interchange their position in the product formation. The reaction can be shown as,

[tex]\rm C a C l _{2} ( a q ) + N a _{2} C O _{3} ( a q ) \rightarrow 2 N a C l ( a q ) + C a C O _{3} ( s )[/tex]

Therefore, the type of reactions is 1. combustion, 2. decomposition, 3. combination, 4. redox and 5. double displacement.

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Answer:

XH₂ = 0.4885

XN₂ = 0.4290

XAr = 0.0825

Explanation:

Step 1: Given data

Step 2: Calculate the total pressure (P)

The total pressure is equal to the sum of the partial pressures of all the gases.

P = pH₂ + pN₂ + pAr = 441.0 Torr + 387.3 Torr + 74.5 Torr = 902.8 Torr

Step 3: Calculate the mole fraction (X) of each gas

We will use the following expression.

Xi = pi / P

where,

Xi: mole fraction of the gas i

pi: partial pressure of the gas i

P: total pressure

XH₂ = pH₂ / P = 441.0 Torr / 902.8 Torr = 0.4885

XN₂ = pN₂ / P = 387.3 Torr / 902.8 Torr = 0.4290

XAr = pAr / P = 74.5 Torr / 902.8 Torr = 0.0825

Answer:

4

Explanation:

24/6 is 4.

Answer:

Mathematically: D = m/v. If you know what liquid you have, you can look up its density in a table. Once you know that, all you have to do to find the mass of the liquid is to measure its volume. Once you know density and volume, calculate mass using this relationship: mass = density • volume.

Explanation:

Answer:

Explanation:

Significant figure implies number of digits that are to be considered. Some rules are required to be considered when writing a given expression to an expected significant figures.

So that:

1) 0.00004050 is 4 significant figures

2) 54.7000 is 6 significant figures

3) 1,000.09 is 6 significant figures

4) 0.039 is 2 significant figures

Dull black surface are good absorbers of radiation.

The process by which energy in the form of electromagnetic radiation is emitted by a heated surface and travels directly to its absorption point at the speed of light.

The rate at which a body absorbs or radiates thermal radiation relies upon the nature of the surface as well.

According to the Kirchhoff's radiation law, the objects, which are good emitters are also good absorbers.

A blackened surface is an excellent absorber as well as an excellent emitter.

A black body refers to a body, which is regarded as a perfect radiator and absorber of electromagnetic radiations, a dull black surface is a good absorber of heat radiation.

Thus, dull black surface is the best surface for absorbing heat radiation.

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Answer:

Answer:

it is Calcium (Ca)

4th period, 2nd group, 2 valence electrons