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3 years ago

As you move from left to right across

Chemistry

1 answer:

Slav-nsk [51]3 years ago

3 0

Answer:

As we move from left to right across the periodic table the number of valance electrons in an atom increase.

Explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase.The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

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The air you breathe is made of 21% oxygen and 78% nitrogen. The oxygen in air is the _____ and the nitrogen is the _____.

jarptica [38.1K]

The answer is solute, solvent

<span>In a solution, a solute the component which is present in lesser amount while a solvent is present in greater amount. </span>Since nitrogen is present in a greater amount than oxygen (78% > 21%), then the oxygen must be the solute and the nitrogen must be the solvent in the air.

5 0

3 years ago

Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce

Andru [333]

Answer:

The empirical formula is C4H8O

Explanation:

Step 1: Data given

Valproic acid is composed of C, H, and O

Mass of the sample = 0.165 grams

Mass of water = 0.166 grams

Mass of CO2 = 0.403 grams

Molar mass of water ( H2O) = 18.02 g/mol

Molar mass of CO2 = 44.01 g/mol

Atomic mass of C = 12.01 g/mol

Atomic mass of O = 16.0 g/mol

Atomic mass H = 1.01 g/mol (H2 = 2.02 g/mol)

Step 2: The equation

CxHyOz + O2 → CO2 + H2O

Step 3: Calculate the number of carbon in the sample

The carbon comes from CO2

Mass C = (12.01 g/mol/44.01 g/mol) * 0.403 grams

Mass C = 0.110 grams

Step 4: Calculate mass of hydrogen in the sample

The hydrogen comes from H2O

Mass H = (2.02/18.02) * 0.166 grams

MAss H = 0.0186 grams

Step 5: Calculate mass of O

The mass of O in the sample = Mass of sample - mass of H - mass of C

The mass of O = 0.165 grams - 0.110 grams - 0.0186 grams

The mass of O = 0.0364 grams

Step 6: Calculate moles

Moles C = 0.110 grams / 12.01 g/mol = 0.00916 moles

Moles H = 0.0186 / 1.01 = 0.0184 moles

Moles O = 0.0364/16.0 = 0.00228 moles

Step 7: Calculate empirical formula

We divide by the smallest amount of moles

C: 0.00916/ 0.00228 = 4

H: 0.0184/0.00228 = 8

O: 0.00228/0.00228 = 1

The empirical formula is C4H8O

7 0

4 years ago

What would be the mass, in grams, of 3.50 x 1025 molecules of chlorine?<br><br> Show your work

Maurinko [17]

Answer:

2059.645g Cl

Explanation:

A mole of any element contains 6.022e23 molecules, so we will divide the given amount of molecules by 6.022e23.

3.5e25 / 6.022e23 = 5.81e1

5.81e1 = 58.1 mol Cl

Now that we have found the amount of moles of Chlorine, we will multiply the number of moles by the molar mass of Chlorine, which is 35.45g/mol.

35.45(58.1) = 2059.645g Cl

4 0

3 years ago

Term that means to break down

astraxan [27]

Answer:

decompose

Explanation:

3 0

4 years ago

Chemical properties

ehidna [41]

The answer is C

Chemical properties or chemical changes are the ones which include changes that alter the identity of a substance. For example: burning of any substance which is also called combustion. You burn a piece of paper it changes its identity. It was cellulose fibres earlier now it’s ash after burning.
You burn petrol it was mixture of hydrocarbons but when burnt it changes to smoke which is just gases like carbon dioxide or nitrogen oxides. This is a chemical change

Changing of states is a physical change not chemical change. Think of meeting of ice the water molecules which were in solid state after melting become water molecules in the liquid state. Similarly, the evaporation or boiling will change the water molecules in the liquid state to the gaseous state also called its vapor state. These do not change identity it’s just the water molecules always may it be any state, solid, liquid or gaseous. So, boiling point and melting point are physical properties not chemical. The identity remains same during these processes.

Mass and color are not chemical properties. They don’t change identity when you measure them. If you weigh yourself on weight u won’t change into something else.

8 0

3 years ago