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1 year ago

Which of these was not proposed by john dalton in 1805?

Chemistry

1 answer:

wel1 year ago

3 0

Answer:

Atoms are made of protons, neutrons and electrons.

Explanation:

The Dalton's atomic theory was an early attempt at describing the properties of atoms. It stipulated that atoms were the smallest indivisible particle of a substance. Chemical reactions occur as a result of a combination or separation of atoms. Atoms of the same element are exactly alike and differ from atoms of other elements. Atoms can neither be created nor destroyed.

As time went on, modern scientific evidence began to modify the original postulates of the Dalton's atomic theory. It was not postulated in 1805 that atoms were composed of subatomic particles; electrons, neutrons and protons. Dalton's theory held the atom to be 'indivisible'. However in 1897, JJ Thompson discovered the electron. Subsequently, the proton and neutrons were discovered. This shows that the atom in itself consisted of even smaller particles.

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Carbon (C): 1sH2sI2pJ H = I = J =

ratelena [41]

Answer:H=2 I=2 J=2

Explanation:

4 0

2 years ago

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Consider 100.0 g samples of two different compounds consisting only of carbon and oxygen. One compound contains 27.2 g of carbon

Pani-rosa [81]

Answer: The ratio of carbon in both the compounds is 1 : 2

Explanation:

Law of multiple proportions states that when two elements combine to form two or more compounds in more than one proportion. The mass of one element that combine with a given mass of the other element are present in the ratios of small whole number. For Example: $Cu_2O\text{ and }CuO$

For Sample 1:

Total mass of sample = 100 g

Mass of carbon = 27.2 g

Mass of oxygen = (100 - 27.7) = 72.8 g

To formulate the formula of the compound, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{27.2g}{12g/mole}=2.26moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{72.8g}{16g/mole}=4.55moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 2.26 moles.

For Carbon = $\frac{2.26}{2.26}=1$

For Oxygen = $\frac{4.55}{2.26}=2.01\approx 2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : O = 1 : 2

Hence, the formula for sample 1 is $CO_2$

For Sample 2:

Total mass of sample = 100 g

Mass of carbon = 42.9 g

Mass of oxygen = (100 - 42.9) = 57.1 g

To formulate the formula of the compound, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{42.9g}{12g/mole}=3.57moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{57.1g}{16g/mole}=3.57moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 3.57 moles.

For Carbon = $\frac{3.57}{3.57}=1$

For Oxygen = $\frac{3.57}{3.57}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : O = 1 : 1

Hence, the formula for sample 1 is $CO$

In the given samples, we need to fix the ratio of oxygen atoms.

So, in sample one, the atom ratio of oxygen and carbon is 2 : 1.

Thus, for 1 atom of oxygen, the atoms of carbon required will be = $\frac{1}{2}\times 1=\frac{1}{2}$

Now, taking the ratio of carbon atoms in both the samples, we get:

$C_1:C_2=\frac{1}{2}:1=1:2$

Hence, the ratio of carbon in both the compounds is 1 : 2

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1 year ago

Write equations that show the processes that describe the first, second, and third ionization energies for a gaseous iron atom.

Nikolay [14]

The ionization energy of an element is the amount of energy required to remove one mole of electrons from the element in its gaseous state. The equations for the first three are:

Fe(g) → Fe⁺(g) + e⁻

Fe⁺(g) → Fe⁺²(g) + e⁻

Fe⁺²(g) → Fe⁺³(g) + e

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1 year ago

If a person looking at a poster sees green instead of yellow and doesn't see red at all, this person most likely has color blind

Inga [223]

People with protanopia are unable to sense any ‘red’ light, people with deuteranopia do not sense ‘green’ light and people with tritanopia cannot sense ‘blue’ light. If a person perceives the color green, then the yellow sensitive nerves must work somewhat effectively since green is a combination of yellow and blue. Red-sensitive nerves are most likely not responding properly for this person. The answer is C.

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1 year ago

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Suppose a container holds 1000 hydrogen molecules (H2) and 1000 oxygen molecules (O2) that react to form water. How many water m

mezya [45]

500 water molecules and the remaining 500 O2 molecules. Remember the ratio of H to O in H2O.

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