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4 years ago

Which statements describe an element? Check all that apply.

Chemistry

1 answer:

Molodets [167]4 years ago

8 0

Answer:

Hello, Your answer will be B,C,E, And F.

Explanation:

An element is a substance whose atoms have same number of protons which means all atoms in an element have same atomic number. Elements are simplest substances which cannot be broken down by physical changes or chemical reactions. Elements are classified by their names and symbols. Hope That Helps!

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How do I find percent mass composition

castortr0y [4]

Answer:

1. Find the molar mass of all the elements in the compound in grams per mole.

2. Find the molecular mass of the entire compound.

3. Divide the component's molar mass by the entire molecular mass.

4. You will now have a number between 0 and 1. Multiply it by 100% to get percent composition.

Explanation:

5 0

3 years ago

Consider the following reaction:C2H4(g) + F2(g) -----------> C2H4F2(g) Delta H = -549 kJEstimate the carbon-fluorine bond ene

frutty [35]

Answer:

Bond energy of carbon-fluorine bond is 485 kJ/mol

Explanation:

Enthalpy change for a reaction, is given as:

$\Delta H_{rxn}=\sum [n_{i}\times (E_{bond})_{i}]-\sum [n_{j}\times (E_{bond})_{j}]$

Where $(E_{bond})_{i}$ and $(E_{bond})_{j}$ represents average bond energy in breaking "i" th bond and forming "j" th bond respectively. $n_{i}$ and $n_{j}$ are number of moles of bond break and form respectively.

In this reaction, one mol of C=C, four moles of C-H and one mol of F-F bonds are broken. One mol of C-C bond, four moles of C-H bonds and two moles of C-F bonds are formed

So, $-549kJ=(1mol\times 614kJ/mo)+(4mol\times E_{C-H})+(1mol\times 154kJ/mol)-(1mol\times 347kJ/mol)-(4mol\times E_{C-H})-(2mol\times E_{C-F})$

or, $-549kJ=(1mol\times 614kJ/mo)+(1mol\times 154kJ/mol)-(1mol\times 347kJ/mol)-(2mol\times E_{C-F})$

or, $E_{C-F}=485kJ/mol$

So bond energy of carbon-fluorine bond is 485 kJ/mol

8 0

3 years ago

What is the name for this molecule? a skeletal model of an 8-carbon zig zag chain. there is a double bond between the first and

yKpoI14uk [10]

The name of the compound by using the IUPAC nomenclature of organic compounds is 1 -octene. The correct option is the last option - 1-octene.

<h3>Nomenclature of Organic compounds</h3>

From the question, we are to determine the name of the given molecule.

To name the compound, we will follow the IUPAC rules.

Some of IUPAC rules are

Find the longest continuous carbon chain. Determine the root name for this parent chain.
For Alkenes (organic compounds with double bond), number the chain of carbons that includes the C=C so that the C=C has the lower position number. Change “ane” to “ene” and assign a position number to the first carbon of the C=C.

The given compound has 8 carbons and a double bond. The root name of the compound is octane.

By IUPAC rules, the compound is an Octene.

Since the double bond is between carbon-1 and carbon-2. The compound becomes 1-octene.

Hence, the name of the compound by using the IUPAC nomenclature of organic compounds is 1 -octene. The correct option is the last option - 1-octene.

Learn more on Nomenclature of Organic compounds here: brainly.com/question/26754333

The diagram for the compound is attached below.

8 0

3 years ago

Which of the following pairs of elements could possibly be in the same group? X has a 1+ ion; Y has a 1- ion. X tends to form a

exis [7]

Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.

5 0

4 years ago

Read 2 more answers

What happens when an atom of sulfur combines with two atoms of chlorine to produce SCI2?

Aloiza [94]

Answer:..A.) Each chlorine atom shares a pair of electrons with the sulfur atom

3 0

2 years ago