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3 years ago

What is the general trend for valence electrons as you go across the periodic table left to right

1 answer:

6 0

The atomic radius decreases across a period from left to right and increases down a given group. The atoms with the largest atomic radii are located in group l and at the bottom of groups. Moving from left to right across a period, electrons are added one at a time to the outer energy shell. Hope this helps!

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Which substance found in fossil fuels can form a harmful acid when the fuel is burned?

dem82 [27]

<span>fossil fuels are mainly organic compounds.Combustion of fossil fuels also produces other air pollutants, such as nitrogen oxides, sulfur dioxide, volatile organic compounds and heavy metals.so,substances which contain sulphur cause to form harmful acids like sulphuric and sulphurus acids</span>

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3 years ago

Read 2 more answers

We can see water change state, from ice to steam. This is a __________ change in matter. A) chemical B) combustion Eliminate C)

Gemiola [76]

Answer: Option (C) is the correct answer.

Explanation:

When chemical composition of a substance is not changing in a chemical reaction then it is known as a physical change.

For example, when water change state, from ice to steam then it means solid state is changing into gaseous state.

Therefore, it is a physical change.

And, a reaction which causes change in chemical composition is known as a chemical change.

For example, $Li + Cl \rightarrow LiCl$

Thus, we can conclude that we can see water change state, from ice to steam. This is a physical change in matter.

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3 years ago

Gaseous ethane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 9.32 g of ethane is

Pie

Answer:

There will remain 8.06 grams of ethane

Explanation:

Step 1: Data given

Mass of ethane = 9.32 grams

Mass of oxygen = 12.0 grams

Molar mass ethane = 30.07 g/mol

Molar mass oxygen = 32.00 g/mol

Step 2: The balanced equation

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

Step 3: Calculate moles ethane

Moles ethane = mass ethane / molar mass ethane

Moles ethane = 9.32 grams / 30.07 g/mol

Moles ethane = 0.3099 moles

Step 4: Calculate moles oxygen

Moles oxygen = 12.0 grams / 32.0 g/mol

Moles oxygen = 0.375 moles

Step 5: Calculate the limiting reactant

For 2 moles ethane we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O

O2 is the limiting reactant. It will completely be consumed ( 0.375 moles)

Ethane is in excess. There will react 2/7 * 0.375 = 0.107 moles

There will remain 0.375 - 0.107 = 0.268 moles

Step 6: Calculate mass ethane

Mass ethane = moles ethane * molar mass ethane

Mass ethane = 0.268 moles * 30.07 g/mol

Mass ethane = 8.06 grams

There will remain 8.06 grams of ethane

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3 years ago

Why steam distillation is usefull for thermally un stable compounds

g100num [7]

The advantage of steam distillation over simple distillation is that the lower boiling point reduces decomposition of temperature -sensitive compounds.

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4 years ago

Temperature also affects the motion of atoms in a gas. Given what you know about temperature, pressure, and volume, which statem

vampirchik [111]

Answer:

C) As a gas is heated, the pressure decreases.

Explanation:

From the choices given, the statement that "as a gas is heated, the pressure decreases is false".

When gases are heated, their molecules expands and the volume of the gas increases. In a fixed container, the pressure of the gases will also increases.

Gases lack internal cohesion and very weak to no intermolecular forces binding them together.
When they are subjected to heat, they gain more energy(kinetic energy) which causes them to begin to spread out.
Thus, they take up even more space allowing volume to increase appreciably.

3 0

3 years ago