Why would a scientist want to replicate another scientist's experiment?

Answer:

Explanation:

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

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

From the question we have

[tex]density = \frac{1000}{255} \\ = 3.921568...[/tex]

We have the final answer as

Hope this helps you

From the arrangement in the periodic table, the increasing order of the atomic radius is Chlorine < Sulfur < Aluminum.

The periodic table has been the arrangement of the elements with increasing atomic numbers and similarities. The elements comprising of the same valence electrons are arranged in the same group.

In the periodic table, on moving down the group there has been the atomic size has been increased with the increase in the shell on each period. The increase in the electrons in the same shell results in the increase in the attraction force and thus, the atomic size decreases across the period.

From the arrangement in the periodic table, the increasing order of the atomic radius is Chlorine < Sulfur < Aluminum.

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Answer:

113 kJ or 113,000J

Explanation:

Since we are condensing it, a physical change in the state of matter is occurring. 113 kJ or 113,000J because of the following equation: Q = 2260 times 50.  2260 is the Heat of Vaporization constant.

Answer:

Total pressure = 22.15 atm

Explanation:

Given data:

Total pressure = ?

Volume of container = 7.85 L

Number of moles of N₂ = 4.45 mol

Number of moles of O₂ = 2.45 mol

Temperature = 307 K

Solution:

Pressure of N₂:

PV = nRT

P = nRT/V

P = 4.45 mol ×0.0821 atm.L/mol.K ×307K / 7.85L

P = 112.16 atm.L/7.85 L

P = 14.28 atm

Pressure of O₂:

PV = nRT

P = nRT/V

P = 2.45 mol ×0.0821 atm.L/mol.K ×307K / 7.85L

P = 61.75 atm.L/7.85 L

P = 7.87 atm

Total pressure = P(N₂) + P(O₂)

Total pressure = P( 14.28 atm)  +  P( 7.87 atm)

Total pressure = 22.15 atm

Answer:

A

Explanation:

The octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds. When discussing the octet rule, we do not consider d or f electrons. Only the s and p electrons are involved in the octet rule, making it useful for the main group elements (elements not in the transition metal or inner-transition metal blocks); an octet in these atoms corresponds to an electron configurations ending with  s2p6 .

Answer:

it's A

The octet rule is a chemical rule of thumb that reflects the theory that main group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. 

The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons and thus the electron configuration of a noble gas. An exception to an octet of electrons is in the case of the first noble gas, helium, which only has two valence electrons.

Explanation:

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Answer:  True

Explanation:

I'm not sure if this was the question.

An isotope of ₂₀⁴⁰X  ⇒₂₀⁴⁴X

The elements in nature have several types of isotopes

Isotopes are atoms that have the same number of protons and a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

In the following element notation,

[tex]\large {{{A} \atop {Z}} \right X}[/tex]

X = symbol of elemental atom

A = mass number

  = number of protons + number of neutrons

Z = atomic number

   = number of protons = number of electrons, on neutral elements

For symbol of isotope X :

₂₀X⁴⁰ : atomic number = 20, mass number = 40

A. ₄₀²⁰X : atomic number = 40, mass number = 20, neutrons=20

B. ₂₀⁴⁰X²⁺ : atomic number = 20, mass number = 40, neutrons=20

C. ₂₁⁴⁰X : atomic number = 21, mass number = 40, neutrons=19

D. ₂₀⁴⁴X : atomic number = 20, mass number = 44, neutrons=22

Answer:

A conductor allows electricity or heat to flow through it easily and an insulator does not.

Explanation:

The difference between a conductor and an insulator is  a conductor allows electricity to flow through it easily and an insulator does not.

Hence, we can conclude that option B is the correct answer.

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Answer: It would have to be Diagram 4

Explanation: That is the only one that looks Ionized and you can hook up a picture of an Ionized Diagram online. That can also help with this question.

Answer:

reactant

Explanation:

oxygen is the one causing the change

Answer:

It is the one that is going into it so i think reactant

Explanation:

Sorry if i am wrong

Answer:

wow ok have fun

Explanation:

Answer:

hiiiiiiiii

Explanation:

thank you

The standard cell notation of a galvanic cell made with aluminum and magnesium is option A. Al3+(aq) | Al(s) || Mg(s) | Mg2(aq).

The right side is the cathode and the left side is the anode. The cell is represented by the convention that the metal is written first, then the metal ions present in the electrolyte. And these two should be separated by a vertical line. Zinc becomes the cathode of the galvanic cell.

Galvanic cells consist of two different metal electrodes connected by a conductive solution electrolyte, which are also connected externally to complete an electrical circuit. Cell notation or cell representation in chemistry is a simple way of representing reactions in an electrochemical cell. The silver half-cell is reduced due to its high standard reduction potential. Tin half-cells are oxidized.

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Answer: C

Explaination:

Answer:

False

Explanation:

The air masses are not responsible for weather , it is cause by the Earth evolution

Answer:

The cathode of a spontaneous electrochemical cell is the cell in which metal cations undergo reduction. The electrons are supplied by the anode. Without much thought, we can conclude magnesium is much less favorably reduced than gold.

The branch of science which deals with chemicals is called chemistry.

The correct option to the question is B.

The system in which the compound is breakdown into its ionic components is called a galvanic cell. In this cell there are two rods, These rodes are as follows:-

In the given question, the cathode is the rode in which electrons enter into the galvanic cell. The cathode is defined as the negatively charged rode.

Hence, the correct option is B that is gold ions.

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Answer:

Explanation:

The ion and the neutral atom both contain 20 protons. Generally the protons stay in the nucleus forever.

The product : Copper oxide

Given

Word equation

Required

The product of the reaction

Solution

The chemical equation can be expressed in terms of:

If we state the word equation  above into a chemical equation(with formula)

CuCO₃ ⇒ CuO + CO₂

This reaction is a type of decomposition reaction

AB⇒A+B

Where the copper carbonate is decomposed into copper oxide and carbon dioxide

As we know, in a chemical reaction, the reactants are on the left and the products are on the right

So that the products of this reaction are copper oxide and carbon dioxide and the reactants are copper carbonate

Answer:

Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog. Air pollution is the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are different types of air pollutants, such as gases, particulates, and biological molecules. Air pollution is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases can come from car and truck exhaust, factories, dust, pollen, mold spores, volcanoes and wildfires. Air pollution can also cause headaches, dizziness, and nausea. ... Long-term health effects from air pollution include heart disease, lung cancer, and respiratory diseases such as emphysema. Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs. The most basic solution for air pollution is to move away from fossil fuels, replacing them with alternative energies like solar, wind and geothermal. Producing clean energy is crucial. But equally important is to reduce our consumption of energy by adopting responsible habits and using more efficient devices.

Its sad of what our world has become

8 sentence paragraph:

Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen, and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog. Some air pollutants are poisonous. Inhaling them can increase the chance you'll have health problems. People with heart or lung disease, older adults, and children are at greater risk from air pollution. Air pollution isn't just outside like the air inside buildings can also be polluted and affect your health.

Answer:

speed is always positive

acceleration may be positive or negative

speed is scalar quantity

accleration vector quantity

Answer:

Answer: B) the temperature of the water

Explanation: The independent variable is the one that is manipulated or changed

Answer:

if the arrangement is symmetrical and the are equal length it is non polar

it the arrows are different lengths and if they do not balance each other or if the arrangement is asymmetrical they are polar

Answer:

Describe the correct electron dot diagrams for the first ten elements of the periodic table. H and Li will each have one dot, He and Be will each have two dots, B will have three, C will have four, N will have five, O will have six, F will have seven, and Ne will have eight. Sulfur has 16 electrons in its atoms.

Answer:

not sure but i guess it's Tellurium

Answer:

ta da

Explanation:

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The outgoing voltage : 72 V

Given

Vp=primary=120 V

Np=10

Ns=6

Required

the secondary voltage

Solution

[tex]\tt \dfrac{V_p}{V_s}=\dfrac{N_p}{N_s}[/tex]

Input the value :

[tex]\tt \dfrac{120}{V_s}=\dfrac{10}{6}\\\\V_s=\dfrac{120\times 6}{10}=72~V[/tex]

Answer:

If the rock can't scratch a knife, but glass, it's a 7-10 (Hard Rock)

It's between Quartz and Topaz.

So the answer is,

Answer:

a

Explanation: