How were the elements in the first periodic table arranged? O A. In order of atomic number B. Alphabetically by element name C. In order of date of discovery O D. In order of atomic mass​

[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

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Answer: The vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.

Explanation:

Given: [tex]\Delta H_{vap}[/tex] = 38.6 kJ/mol

[tex]T_{1} = 26.3^{o}C = (26.3 + 273) K = 299.3 K[/tex]

[tex]T_{2} = 78.4^{o}C = (78.4 + 273) K = 351.4 K[/tex]

Formula used to calculate the vapor pressure of ethanol is as follows.

[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\[/tex]

Substitute the values into above formula as follows.

[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\ \\ln \frac{760 torr}{P_{1}} = \frac{38600 J}{8.314 J/mol K}[\frac{1}{299.3} - \frac{1}{351.4}]\\\frac{760}{P_{1}} = 3.18\\P_{1} = 238.3 torr[/tex]

Thus, we can conclude that the vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.

Temperature change

Answer:

Then, at some point, these higher energy electrons give up their "extra" energy in the form of a photon of light, and fall back down to their original energy level.

Explanation:

When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital.

Answer:

[tex]\boxed {\boxed {\sf 0.601 \ g \ As}}[/tex]

Explanation:

We want to convert atoms of arsenic to mass in grams. We have to complete 3 steps.

The first step is converting atoms to moles. We use Avogadro's Number for this. This number is 6.022*10²³ and it is the number of representative units (molecules, atoms, etc.) in 1 mole of a substance. In this problem, the particles are atoms of arsenic. So, 1 mole of arsenic contains  6.022*10²³ atoms of arsenic. Use this information to make a ratio.

[tex]\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

Multiply by the number of atoms provided in the problem: 4.83 × 10²¹

[tex]4.83 *10^{21} \ atoms \ As *\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

The units of atoms of arsenic (atoms As) cancel.

[tex]4.83 *10^{21} *\frac{1 \ mol \ As}{{6.022*10^{23}} }[/tex]

Condense into 1 fraction.

[tex]\frac{4.83 *10^{21} }{{6.022*10^{23}} } \ mol \ As[/tex]

[tex]0.008020591166 \ mol \ As[/tex]

The next step is converting moles to grams. We use the molar mass for this, which is provided. There are 74.92 grams of arsenic in 1 mole of arsenic, so we can make another ratio.

[tex]\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

Multiply by the number of moles we calculated.

[tex]0.008020591166 \ mol \ As*\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

The units of moles of arsenic (mol As) cancel.

[tex]0.008020591166 *\frac {74.92 \ g\ As}{ 1}[/tex]

[tex]0.6009026901 \ g \ As[/tex]

The original measurement of atoms (4.83 × 10²¹ ) has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place (0.6009026901) tells us to round the 0 to a 1.

[tex]0.601 \ g \ As[/tex]

There are approximately 0.601 grams of arsenic.

Answer:

sorry i dint understand can u ask it in a simpler way

Explanation:

Answer:

Explanation:

Because you only have one repeat unit, n=1. 2n-1 becomes 2(1)-1 which is equal to one, meaning one molecule of H2O is produced, as is shown by the top condensation polymerisation reaction.

If you had two repeat units, n=2 so 2n-1=3. Three H2O molecules are produced because you would need two molecules of each reactant so three condesation reactions would occur and three molecules of H2O would be released.

Answer:

1. How do metals and non-metals react with acids?

Ans : Non metals does not react with acids while metals react with acids and produce hydrogen gas that burns with a 'pop'sound.

2. Write and explain the chemical equation for the reaction of magnesium with sulphuric acid and aluminium with hydrochloric acid.

Magnesium + sulphuric acid = Hydrogen + salt

Mg(s) + H2SO4 (aq) MgSO 4(aq) +H2 (g)

Aluminium + Hydrochloric acid = Hydrogen + Aluminium chloride

2Al(s)+6HCl(aq)→2AlCl3(aq)+3H2(g)

Answer:

Metals react with acid but non metals donot react with acid because

when a substance, reacts with acids it provides electrons to the H+ ions produced by the acids. Non-metals are acceptors of electrons and hence, they cannot donate electrons.

Explanation: H2SO4 + Mg(OH)2 = H2O + MgSO4. 2Al+6HCl→2AlCl3+3H2 2 A l + 6 H C l → 2 A l C l 3 + 3 H 2

Answer:

Inference

Explanation:

I mean, it's not difficult.

A theory is an unproven explanation.

An inference is a guess/educated guess where you don't have all the facts.

For example, if "Bob" is caught in the kitchen with a ketchup stain on his shirt, you are inferencing that he used the ketchup.

However, if you see a ketchup bottle nearby or saw it earlier, then it is not, because you already have the facts that ketchup was used.

Answer:

Hydrogenation

Explanation:

Look up the definition to confirm

Answer:

5 kg of feather

Explanation:

Answer:

no lo se yo hablo en español no en ingles

Answer: Solve problems

1st one

2_2_2

2nd one

3_1_1_3

i looked it up

Answer:

its a chemical change.

hope it helps.

Answer: it is a chemical change because it involves chemical process

Explanation:

Answer:

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Answer: Decomposition is the answer

Explanation: why because aluminium hydroxide would decomposes in the presence of heat and would form an oxide which is aluminium oxide and would also form water as a product.

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Answer:

[tex]\boxed {\boxed {\sf 79,420 \ J}}[/tex]

Explanation:

We are given the mass, a change in temperature, and the specific heat of water. We should use the following formula to solve this problem.

[tex]q=mc\Delta T[/tex]

In this formula, m is the mass, c is the specific heat, and ΔT is the change in temperature.

We know there are 250 grams of water and the specific heat of water is 4.18 J/g · °C.

We are given two temperature, so have to find the change in temperature. This is the difference between the initial temperature and final temperature. The water is heated from 24 °C to 100 °C. Therefore, the initial is 24 and the final is 100.

[tex]\bullet \ \Delta T= T_{final} - T_{initial} \\\bullet \ \Delta T=100 \textdegree C - 24 \textdegree C\\\bullet \Delta T= 76 \textdegree C[/tex]

Now we know all three of the variables and we can substitute them into the formula.

[tex]\bullet \ m= 250 \ g\\ \bullet \ c=4.18 \ J/g \textdegree C \\ \bullet \ \Delta T= 76 \textdegree C[/tex]

[tex]q= (250 \ g)( 4.18 \ J/g * \textdegree C)( 76 \textdegree C)[/tex]

Multiply the first two numbers together. The units of grams will cancel.

[tex]q= (1045 \ J/\textdegree C)(76 \textdegree C)[/tex]

Multiply again. This time, the units of degrees Celsius cancel.

[tex]q= 79420 \ J[/tex]

79, 420 Joules of heat must be added.

Answer:

(6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Explanation:

Question; From the given options, the chemical reaction in the question is presented as follows;

C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l), given that we have;

[tex]\Delta \text H _f^{\circ}[/tex] for C₆H₁₂O₆ = -1,273.02 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for O₂(g) = 0 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for CO₂(g) = -393.5 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for H₂O(l) = -285.83 kJ/mol

The heat or enthalpy of a reaction,  is given as follows;

[tex]\Delta\text H_{rxn}^{\circ} = \sum \text n \cdot \Delta \text H _f^{\circ}(\text {products}) - \sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex]

Therefore, the equation which should be used to calculate [tex]\Delta\text H_{rxn}^{\circ}[/tex], is given as follows;

[tex]\sum \text n \cdot \Delta \text H _f^{\circ}(\text {products})[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol)

[tex]\sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex] = (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Therefore;

[tex]\Delta\text H_{rxn}^{\circ}[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Answer:

Metals , silver and copper which allows to pass the electricity through it is called good conductor of electricity .

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Answer:

See explanation

Explanation:

In Bohr's theory, electrons are found in specific regions in space called orbits. These orbits are also called energy levels. An electron may move from one energy level to another by absorbing or emitting energy.

In the wave mechanical model, electrons are not found in a particular region in space according to Heisenberg's uncertainty principle.

We rather define a certain region in space where there is a high probability of locating the electron. This region in space where there is a high probability of locating the electron is called an orbital.

Hence, in the Bohr's model of the atom,electrons can surely be found in orbits while in the wave mechanical model, the orbital is a probability function that describes a region in space where an electron may be found.

Answer:

The average atomic mass includes all of the isotopes of that atom which exist in nature. Almost all elements have at least two isotopes which naturally occur. Recall that isotopes are atoms with the same atomic number (protons), but a different number of neutrons.

Answer:

Chemistry plays an important and useful role towards the development and growth of a number of industries. This includes industries like glass, cement, paper, textile, leather, dye etc. We also see huge applications of chemistry in industries like paints, pigments, petroleum, sugar, plastics, Pharmaceuticals.

Answer:

the answer is c kept in blue and with light

Answer: Solution D has the highest concentration of all.

Explanation:

The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (mL)}}[/tex]  .....(1)

Molarity of permanganate solution = 0.1 M

Volume of solution = [tex]100 cm^3=100mL[/tex]        (Conversion factor: [tex]1mL=1cm^3[/tex])

Putting values in equation 1, we get:

[tex]0.1=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.1}{1000}=0.01mol[/tex]

Molarity of permanganate solution = 0.01 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]0.01=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.01}{1000}=0.001mol[/tex]

Molarity of permanganate solution = 2 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2}{1000}=0.2mol[/tex]

Molarity of permanganate solution = 2.5 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2.5=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2.5}{1000}=0.25mol[/tex]

The solution having the highest number of moles will have the highest concentration for the same volume.

Thus, solution D has the highest concentration of all.

Answer:

Density of the solid=[tex]2.78 g/cm^3[/tex]

Explanation:

We are given that

Mass of sample of metal=4.369 g

Volume in the flask, V=126.4 ml

Mass of water, flask, and metal=268.5 g

Mass of flask=139.3 g

Density of water=1.000 g/mL

We have to find the density of the solid.

Mass of water=268.5-4.369-139.3=124.831 g

Volume of water=[tex]\frac{Mass\;of\;water}{density\;of\;water}[/tex]

Volume of water=[tex]\frac{124.831}{1}=124.831 mL[/tex]

Volume of solid=126.4 ml-124.831 mL

=1.569mL

Now,

Density of the solid=[tex]\frac{mass\;of\;solid}{volume\;of\;solid}[/tex]

=[tex]\frac{4.369}{1.569}[/tex]

[tex]=2.78g/mL[/tex]

1mL=1 cubic cm

Therefore,

Density of the solid=[tex]2.78 g/cm^3[/tex]

Answer:

[tex]10 {7}^{2} = [/tex]