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3 years ago

Which of these statements best describes the relationship between elements, compounds, and pure substances?

Chemistry

2 answers:

Tamiku [17]3 years ago

7 0

Answer:

Pure substances can be divided into two groups: elements and compounds.

Explanation:

Pure substances can be recognized because they have a definite constant composition, as can be seen in the formula, and distinct chemical properties.

For example, H₂O is a pure substance where the relation of 2 atoms of Hydrogen to 1 atom of Oxygen is always true. O₂ is also a pure substance because 1 molecule of O₂ always contains two atoms of Oxygen.

As we can see from above, pure substances can be formed by one or more types of atoms. Substances formed by 2 or more types of atoms are known as compounds (e.g. H₂O, CO₂). Substances formed by 1 type of atoms are known as elements (e.g. Na, O₂, O₃).

Compounds and elements are kinds of pure substances, so they inherit all properties from them (definite constant composition, distinct chemical properties).

olchik [2.2K]3 years ago

5 0

pure substances can be divided into two groups; elements and compounds

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poizon [28]

Answer:

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3 years ago

Could someone explain what oxidation numbers are and what these questions are asking of me?

Oxana [17]

The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound.

<u>Explanation:</u>

The oxidation number of an atom is the charge that atom would have if the compound was composed of ions. 1. The oxidation number of an atom is zero in a neutral substance that contains atoms of only one element. The oxidation number of simple ions is equal to the charge on the ion.

The oxidation number of a mono atomic ion equals the charge of the ion. The oxidation number of H is +1, but it is -1 in when combined with less electro negative elements. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides. The oxidation number of a Group 1 element in a compound is +1.

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3 years ago

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Olegator [25]

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Explanation:

You my find in the attached picture the structures of the compounds, names and also the variation of their boiling points.

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Learn more about:

boiling points in organic compounds

brainly.com/question/2153588

#learnwithBrainly

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3 years ago

Unit: Chemical Quantities

Vaselesa [24]

Answer:

(See explanation for further details)

Explanation:

1) The quantity of moles of sulfur is:

$n = \frac{1.20\times 10^{24}\,atoms}{6.022\times 10^{23}\,\frac{atoms}{mol} }$

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$x = (1.5\,moles)\cdot \left(6.022\times 10^{23}\,\frac{atoms}{mole} \right)$

$x = 9.033\times 10^{23}\,atoms$

3) The quantity of moles of carbon monoxide is:

$n = \frac{4.15\times 10^{23}\,molecules}{6.022\times 10^{23}\,\frac{molecules}{mol} }$

$n = 0.689\,moles$

4) The number of molecules of sulfur dioxide is:

$x = (2.25\,moles)\cdot \left(6.022\times 10^{23}\,\frac{molecules}{mole} \right)$

$x = 1.355\times 10^{24}\,molecules$

5) The quantity of moles of sodium chloride is:

$n = \frac{2.4\times 10^{23}\,molecules}{6.022\times 10^{23}\,\frac{molecules}{mol} }$

$n = 0.399\,moles$

6) The number of formula units of magnesium iodide is:

$x = (1.8\,moles)\cdot \left(6.022\times 10^{23}\,\frac{f.u.}{mole} \right)$

$x = 1.084\times 10^{24}\,f.u.$

7) The quantity of moles of potassium permanganate is:

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$x = 1.506\times 10^{23}\,molecules$

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$n = 0.609\,moles$

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$x = (3.52\,moles)\cdot \left(6.022\times 10^{23}\,\frac{molecules}{mole} \right)$

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tester [92]

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