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Rubbing the balloons against the woolen fabric or your hair creates static electricity. This involves negatively charged particles (electrons) jumping to positively charged objects. When you rub the balloons against your hair or the fabric they become negatively charged, they have taken some of the electrons from the hair/fabric and left them positively charged.

What would be a result of this simple static electricity experiment?

A) Both your hair and the balloon would be negatively charged and static would cause them to separate.

B) Rubbing the balloons against the woolen fabric or your hair creates heat energy.

C) Your positively charged hair would be attracted to the negatively charged balloon and would rise up to meet the balloon.

D) Static electricity is the movement of the charged particles between the objects.

Air, soil, plants, fuels and water are examples of natural resources. Some of these (ex. air & water) are renewable. Some however are nonrenewable (ex. fuels). If not conserved and protected, we may lose some of these resources to pollution or depletion.

The Earth's natural resources include air, water, soil, minerals, fuels, plants, and animals. Conservation is the practice of caring for these resourcesso all living things can benefit from them now and in the future. ... These are renewable resources. Otherresources, such as fossil fuels, cannot be replaced at all.

Source: National Geography

Answer:

He is determining physical properties that are sufficient to identify the metal.

Explanation:

So, the right choice is:

He is determining physical properties that are sufficient to identify the metal.

A! He is determining physical that are sufficient to identify the metal.

Answer:

256.52 g/m

Explanation:

Each S has a molecular mass of 32.056 g/mol so multiply that by 8 and you get 256.52.

Answer:

[tex]\Delta H\textdegree = -2856.8\;\text{kJ}[/tex] per mole reaction.

[tex]\Delta H\textdegree = -22.3\;\text{kJ}[/tex] per mole reaction.

Explanation:

What is the standard enthalpy of formation [tex]\Delta H_f\textdegree{}[/tex] of a substance? [tex]\Delta H_f\textdegree{}[/tex] the enthalpy change when one mole of the substance is formed from the most stable allotrope of its elements under standard conditions.

Naturally, [tex]\Delta H_f\textdegree{} = 0[/tex] for the most stable allotrope of each element under standard conditions. For example, oxygen [tex]\text{O}_2[/tex] (not ozone [tex]\text{O}_3[/tex]) is the most stable allotrope of oxygen. Also, under STP [tex]\text{O}_2[/tex]  is a gas. Forming [tex]\text{O}_2\;(g)[/tex] from itself does not involve any chemical or physical change. As a result, [tex]\Delta H_f\textdegree{} = 0[/tex] for [tex]\text{O}_2\;(g)[/tex].

Look up standard enthalpy of formation [tex]\Delta H_f\textdegree{}[/tex] data for the rest of the species. In case one or more values are not available from your school, here are the published ones. Note the state symbols of the compounds (water/steam [tex]\text{H}_2\text{O}[/tex] in particular) and the sign of the enthalpy changes.

How to calculate the enthalpy change of a reaction [tex]\Delta H_\text{rxn}[/tex] (or simply [tex]\Delta H[/tex] from enthalpies of formation?

For the first reaction:

Try these steps for the second reaction:

[tex]\Delta H_\text{rxn} = -22.3\;\text{kJ}\cdot\text{mol}^{-1}[/tex].

flow of charge of electrons cause current in wire.

Electric current in a wire causes  an electrons flow because of electrical attraction and repulsion. Option D is correct.

Electric current is the flow of electrons through a conductor. Conductors are materials that allow electrons to flow freely. Wires are made of conductors, such as copper or aluminum. When a voltage difference is applied to a wire, it creates an electric field. The electric field causes the electrons in the wire to move.

The electrons move from the negative side of the voltage source to the positive side. The movement of electrons through a wire is what creates an electric current. The amount of current that flows through a wire depends on the strength of the electric field and the resistance of the wire. Electrons are negatively charged particles that orbit the nucleus of an atom. Option D is correct.

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Answer:

471 g

Explanation:

When 8.73 moles of benzene react with excess oxygen, approximately 471.42 grams of water will be produced.

In order to find out how many grams of water are produced from the reaction of 8.73 moles of benzene (C6H6) with excess oxygen (O2), we need to know the balanced chemical reaction. The combustion reaction for benzene looks like this:

C6H6 + 7.5O2 -> 6CO2 + 3H2O

From the balanced combustion reaction, it can be seen that for each mole of benzene reacting, 3 moles of water are produced. So, if 8.73 moles of benzene react, it would yield 3 times this many moles of water: 8.73*3 = 26.19 moles of water.

As the molar mass of water (H2O) is approximately 18 g/mole, we can calculate grams of water by multiplying moles of water and molar mass of water.

26.19 moles * 18 g/mole = 471.42 grams of water

So, approx 471.42 grams of water can be produced when 8.73 moles of benzene react with excess oxygen.

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Solution:

Density of iron( d)=?

Specific gravity of iron=7.87

Density of water at 4°C=1g/cm^3

we have,

specific gravity =density of object/density of water at 4°C

or,7.87=d/1

or, d=7.87g/cm^3

Again,

density=mass/ volume

or,7.87=7/V

or,V=7/7.87

or,V=0.88cm^3

therefore, volume occupied by iron is 0.88cm^3

Answer:

The last choice is oxidation.

Explanation:

The this is a reaction in which the oxidation number of chromium metal

( 0 ) goes the an oxidation number of 3 in Cr3+.

Answer : The correct option is, [tex]Cr(s)\rightarrow Cr^{3+}(aq)+3e^-[/tex]

Explanation :

Redox reaction : It is a reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is a reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is a reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

The correct oxidation-half reaction will be :

[tex]Cr(s)\rightarrow Cr^{3+}(aq)+3e^-[/tex]

In this half oxidation reaction, the oxidation state of 'Cr' changes from (0) to (+3) that means the oxidation state increases that means it shows oxidation.

Answer:

4.78 %.

Explanation:

mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.

mass % = (mass of solute/mass of solution) x 100.

mass of MgSO₄ = 50.0 g,

mass of water = d.V = (0.997 g/mL)(1000.0 mL) = 997.0 g.

mass of the solution = mass of water + mass of MgSO₄ = 997.0 g + 50.0 g = 1047.0 g.

∴ mass % = (mass of solute/mass of solution) x 100 = (50.0 g/1047.0 g) x 100 = 4.776 % ≅ 4.78 %.

The percent mass of [tex]MgSO_4[/tex] in the solution is approximately [tex]4.77\%[/tex].

To find the percent mass of [tex]MgSO_4[/tex] in the solution, we need to calculate the total mass of the solution and then determine the mass of [tex]MgSO_4[/tex] in it.

Given:

[tex]Mass \ of \ MgSO_4 = 50.0 \ g[/tex]

[tex]Volume \ of \ water = 1000.0\ mL[/tex]

[tex]Density\ of\ water = 0.997 \ g/mL[/tex]

First, we'll find the mass of the water using its density:

[tex]\[ \text{Mass of water} = \text{Density} \times \text{Volume} \][/tex]

[tex]\[ \text{Mass of water} = 0.997 \, \text{g/mL} \times 1000.0 \, \text{mL} \][/tex]

[tex]\[ \text{Mass of water} = 997 \, \text{g} \][/tex]

Now, we'll calculate the total mass of the solution:

[tex]\[ \text{Total mass of solution} = \text{Mass of MgSO}_4 + \text{Mass of water} \][/tex]

[tex]\[ \text{Total mass of solution} = 50.0 \, \text{g} + 997 \, \text{g} \][/tex]

[tex]\[ \text{Total mass of solution} = 1047 \, \text{g} \][/tex]

Next, we'll determine the percent mass of [tex]MgSO_4[/tex] in the solution:

[tex]\[ \text{Percent mass of MgSO}_4 = \left( \frac{\text{Mass of MgSO}_4}{\text{Total mass of solution}} \right) \times 100\% \][/tex]

[tex]\[ \text{Percent mass of MgSO}_4 = \left( \frac{50.0 \, \text{g}}{1047 \, \text{g}} \right) \times 100\% \][/tex]

[tex]\[ \text{Percent mass of MgSO}_4 = 4.77\% \][/tex]

Answer:

C-a tree grows taller

Explanation:

Cell division is cellular reproduction, so C is the only option involving growth/reproducing.

Answer:

The correct answer to this question is: C "A Tree Grows Taller"

Explanation:

Cell division is cellular reproduction.  All mammals eat to take in energy. Plants take in energy from the sun to use and collect the same energy which is then used to do various things. The tree is using Mitosis to its advantage so it can grow. That is why C is the correct answer.

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A I believe is correct

Answer:

metal spoon because travels fastest through solid objects

Explanation:

Answer:hi guys it is both objects are the same temperature

Explanation:

Heat transfers from a warmer object to a colder one (such as an ice cube) until both objects are at the same temperature. This is a process known as conduction.

When an ice cube is placed on an object that is warmer than it, heat will be transferred from the warmer substance to the ice cube. This process will continue until both objects are the same temperature. This is explained by the physics law of heat transfer, specifically conduction, which is the process where heat energy is transferred between substances in direct contact with each other.

The warmer object will lose heat to the colder object (the ice cube) until equilibrium is reached and both objects have the same temperature. It may also coincide with other options like the ice melting or ice reaching 0°C, but this depends on the initial temperature of the warmer object.

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Answer:

22.94 L.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and T are constant, and have two different values of V and P:

P₁V₁ = P₂V₂

P₁ = 367.0 mm Hg, V₁ = 49.0 L.

P₂ = 784.0 mm Hg, V₂ = ??? L.

∴ V₂ = P₁V₁/P₂ = (367.0 mm Hg)(49.0 L)/(784.0 mm Hg) = 22.94 L.

Answer:

Graphics can sometimes convey more information in a brief amount of space than an author can explain in a paragraph.

Answer:

D. Catalysts speed up the rate of reactions by lowering the amount of energy required for the reaction to proceed.

Explanation:

A catalyst is a substance that:

A catalyst provides an alternative reaction pathway that has a lower activation energy than the uncatalyzed reaction.

The figure shows how the energy of the reactants and products change during a reaction.

Answer:

- 0.0413°C ≅ - 0.041°C (nearest thousands).

Explanation:

ΔTf = Kf.m,

Where,

ΔTf is the change in the freezing point.

Kf is the freezing point depression constant (Kf = 1.86 °C/m).

m is the molality of the solution.

Molality is the no. of moles of solute per kg of the solution.

∴ molality (m) = no. of moles of solute/kg of solvent = (0.04685 mol)/(2.11 kg) = 0.0222 m.

∴ ΔTf = Kf.m = (1.86 °C/m)(0.0222 m) = 0.0413°C.

∴ The freezing point of the solution = the freezing point of water - ΔTf = 0.0°C - 0.0413°C = - 0.0413°C ≅ - 0.041°C (nearest thousands).

Answer:

-0.041

Explanation:

Answer:

The correct answer is B

Explanation:

Nuclear Fusion is a raection in which two or more atomic nuclei are combined together to form a heavier nuclei.

The study of chemicals and bonds is called chemistry. The element is made of electrons, protons, and neutrons.

The correct answer is option B that is involves the collision of two nuclei.

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.

Fusion means the joining of two-component and according to the question, the correct answer is option B.

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lowest melting point-covalent solids

highest melting point-ionic solids

Molecular solids like ice tend to have lower melting points due to weaker intermolecular forces, while ionic solids such as sodium chloride have high melting points due to strong ionic bonds. Network covalent solids also have high melting points, whereas amorphous solids soften over a range of temperatures.

The melting point of a solid is the temperature at which the solid changes into a liquid. It reflects how much kinetic energy is required for the particles within a solid to overcome the attractive forces keeping them in place. In general, molecular solids, such as ice (melting point of 0°C), tend to have lower melting points due to weaker intermolecular forces like hydrogen bonds or London dispersion forces. On the other hand, ionic solids, such as sodium chloride (melting point of 801°C), display the highest melting points because the ionic bonds between their ions are very strong.

Network covalent solids often have high melting points as well since the atoms within the network are bonded by covalent bonds that require significant energy to break. By contrast, amorphous solids like butter do not have a sharp melting point but rather soften over a range of temperatures due to the lack of a well-ordered molecular structure like that seen in crystalline solids.

Answer:

2.88 L.

Explanation:

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant.

T is the temperature of the gas in K.

P₁V₁ = P₂V₂

P₁ = 1.0 atm, V₁ = 7.2 L.

P₂ = 2.5 atm, V₂ = ??? L.

∴ V₂ = P₁V₁/P₂ = (1.0 atm)(7.2 L)/(2.5 atm) = 2.88 L.

Answer:

34.44 g.

Explanation:

Fe + S → FeS,

It is clear that 1.0 mol of Fe reacts with 1.0 mol of S to produce 1.0 mol FeS.

no. of moles of Fe = mass/atomic mass = (60.0 g)/(55.845 g/mol) = 1.074 mol.

no. of moles of FeS = mass/molar mass = (90.0 g)/(87.91 g/mol) = 1.024 mol.

∵ Fe reacts with S with (1: 1) molar ratio.

∴ The no. of moles of S needed to react with Fe is 1.074 mol.

∴ The no. of grams of S needed = no. of moles x molar mass = (1.074 mol)(32.065 g/mol) = 34.44 g.

Answer:

The answer is:

A. 30 grams

Explanation:

The mouth (can also be a delta or estuary) is where a stream empties into another body of water.

Answer:

The given blank can be filled with mouth.

Explanation:

A body of water comprising surface water flowing within the banks and bed of a channel is known as a stream. The stream comprises groundwater and surface fluxes, which reacts towards the geomorphological, geological, biotic, and hydrological controls. The lengthy and large streams are generally termed as rivers. The mouth of the stream is considered as the point at which the stream releases probably through a delta or an estuary, into a standing water body like ocean or lake.

Answer:

When substances combine to form new substances, the properties of the reactants are preserved.

Explanation:

When the two elements Na and Cl combine, they produce a stable, crystalline solid known commonly as table salt.  This explains as when substances combine to form new substances, the properties of the reactants are preserved. Therefore, option A is correct.

Elements are pure substances that cannot be broken down into simpler substances by chemical means. They are made up of atoms, which have a specific number of protons in their nucleus that defines their atomic number.

In a chemical reaction, the atoms that form the first substances are regrouped into other molecules, and these new substances have various properties from those of the reactants. The total number of all types of atoms is kept, and thus the mass does not change.

Thus, option A is correct.

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Answer:

= 28.745 g

Explanation:

Half life is the time taken by a radioactive element to decay by half the original amount.

Therefore;

New mass = Original mass × (1/2)^n

Where n is the number of half lives, in this case, n = 20/5.27 = 3.795

Therefore;

New mass = 399 g × (1/2)^3.795

                = 28.745 g

Answer:

[tex]\boxed{\text{417 kJ}}[/tex]

Explanation:

There are three heat transfers in this process:

Total heat = warming the ice + melting the ice + warming the water  

       q        =           q₁               +           q₂             +              q₃

       q        =       mC₁ΔT₁          +        mΔHfus       +          mC₂ΔT₂

Let's calculate these heat transfers separately.

Data:

      m = 1 kg = 1000 g

     C₁ = 2.108 J·°C⁻¹g⁻¹

     C₂ = 4.184 J·°C⁻¹g⁻¹

ΔHfus = 333 J/g

Tmax =   15 °C

 m.p. =    0 °C

Tmin = -10 °C

Calculations:

ΔT₁ = 0 – (-10) = 10 °C

q₁ = 1000 × 2.108 × 10 = 21 080J = 21.08 kJ

q₂ = 1000 × 333 = 333 000 J =333 kJ

ΔT₂ = 15 - 0 = 15 °C

 q₃ = 1000 × 4.184 × 15 = 62 760 J = 62.76 kJ

q = 21.08 + 333 + 62.76 = 417 kJ

You must add [tex]\boxed{\textbf{417 kJ}}[/tex].

Answer:

CaF₂+H₂SO₄ → CaSO₄+2HF     ΔH = +157.7KJ

Explanation:

Energy changes in chemical reactions is one of the most important issues in thermodynamics  especially the enthalpy of reaction (ΔHrxn)

           CaF₂+H₂SO₄+157.7KJ → CaSO₄+2HF

which can be expressed in alternate form as following

CaF₂+H₂SO₄ → CaSO₄+2HF     ΔH = +157.7KJ

Answer:1. Age of earth 2. D. Newer, Older 3. True

Explanation:

Scientists use rock layers to determine the age of Earth. Fossils in newer, or higher, rock layers are typically younger than those in older or deeper layers. And yes, new evidence can indeed lead to changes in scientific understanding.

1. Scientists use rock layers primarily to determine the age of Earth. They do this through a method called stratigraphy, wherein they study the arrangement of rock layers and relative ages to understand the Earth's past. So, the correct answer is C. The age of Earth.

2. Generally, fossils found in newer layers of rock are estimated to be younger than those found in deeper (or older) layers. As sediment is deposited over time, newer layers form on top of older ones, and as a result, newer fossils are typically found closer to the surface. So the correct answer is B. newer, younger.

3. True. New evidence can definitely lead to a change in scientific knowledge. Science is a dynamic and evolving field and new discoveries or data can modify or even completely change previously held theories and understandings.

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The average rate of the reaction over the first 580 seconds is approximately [tex]2.07 \times 10^{(-3)} M/s[/tex]. Thus, option C is correct.

To find the average rate of the reaction over the first 580 seconds, we can use the formula:

[tex]\[ \text{Average rate} = \frac{\text{Change in concentration}}{\text{Change in time}} \][/tex]

Given the concentrations at 0 s and 580 s, and the corresponding times, we can calculate the change in concentration and change in time:

Change in concentration = 1.8 M - 0.6 M = 1.2 M

Change in time = 580 s - 0 s = 580 s

Now, we can calculate the average rate:

Average rate = [tex]\(\frac{1.2 \text{ M}}{580 \text{ s}}\)[/tex]

Average rate = [tex]\(2.07 \times 10^{-3}\) M/s[/tex]

Therefore, the average rate of the reaction over the first 580 seconds is approximately [tex]2.07 \times 10^{(-3)} M/s[/tex]. Since this is closest to option C [tex](2.0 \times 10^{(-3)})[/tex], the answer is C.

Answer:

Cr

Mn⁺¹

Fe⁺²

Explanation:

Answer:

3.8 liters

Explanation:

According to Avogadro’s Law  of gases

at constant temperature and pressure, the volume of all gases constitutes an equal number of molecules. In other words, the volume of any gas is directly proportional to the number of molecules of that gas.

∴ V ∝ n   or (V₁/V₂) = (n₁/n₂)

V₁= 2.5 L

n₁= 0.3 mol

n₂= 0.3 mol + 0.15 mol = 0.45 mol

using cross multiplication

(2.5 L / V₂) = (0.3 mol / 0.45 mol)

V₂= 3.8 L

∴ The right choice is 3.8 liters

Answer:

3.8 liters

Explanation:

you can find the run by subtracting the X coordinate of the left point from that of the right point

You can find by subtracting the variable