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DiKsa [7]
3 years ago
6

NEED HELP QUICK!!!!!!!!!!!!!!

Chemistry
1 answer:
Zigmanuir [339]3 years ago
3 0
The answer is Index fossils its the only answer it could be

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Match with the correct definition.
andre [41]

Answer:

Ionic bonding: C

Covalent bonding: B

Metallic bonding: D

Pauli exclusion principle: A

Explanation:

All the electrons in 1 atom are characterized by a series of 4 numbers, known as quantum numbers. These numbers (n, l, ml, ms) describe the state of each electron (in which level, sublevel, orbital it is and its spin). For 2 electrons to coexist in the same atom they must differ in at least of these numbers. If they occupy the same level, sublevel and orbital, then they must have different (and opposite) spins. This is known as Pauli exclusion principle.

Also, to gain stability atoms can gain, lose or share electrons. In doing so they form bonds. There are 3 kinds of bonds:

  • Ionic bonding: these are formed between metals and nonmetals. Metals tend to lose electrons and form cations (positive ions) and nonmetals tend to gain electrons and form anions (negative ions). Cations and anions attract each other due to <em>electrostatic forces</em> between <em>oppositely charged ions</em>.
  • Covalent bonding: these are formed between nonmetals, which share pairs of electrons so as to reach the <em>electron configuration</em> of the closest noble gas (the most stable electron configuration).
  • Metallic bonding: valence electrons are loose in metals, so they move together as a "sea of electrons", acting as <em>"glue"</em> of the remaining positive <em>cores</em> (electrons that are negative charges serve to attract the positive charges of the cores).
8 0
3 years ago
Calcium Oxide will react with ammonium chloride to produce ammonia gas, water vapor, and calcium chloride. If only 16.3 g of amm
Vaselesa [24]

Answer:

                     %age Yield  =  22.72 %

Explanation:

                    The balance chemical equation is as follow;

                           2 NH₄Cl + CaO → 2 NH₃ + CaCl₂ + H₂O

Step 1: <u>Calculate Moles of CaO, NH₄Cl and NH₃;</u>

CaO:

        Moles  =  Mass / M.Mass

        Moles  =  112 g / 56.07 g/mol

        Moles  =  1.99 moles of CaO

NH₄Cl:

        Moles  =  Mass / M.Mass

        Moles  =  224 g / 53.49 g/mol

        Moles  =  4.18 moles of NH₄Cl

NH₃:

        Moles  =  Mass / M.Mass

        Moles  =  16.3 g / 17.03 g/mol

        Moles  =  0.95 moles of NH₃

Step 2: <u>Calculate Limiting reagent as:</u>

According to equation.

                   2 moles of NH₄Cl reacts with  =  1 mole of CaO

So,

              4.18 moles of NH₄Cl will react with  =  X moles of CaO

Solving for X,

                     X =  4.18 mol × 1 mol / 2 mol

                     X  =  2.09 mol of CaO

This means that none of the given reagent is limiting reagent. They both are almost equal in number of moles.

Step 3: <u>Calculate Theoretical Yield of NH₃ as;</u>

According to equation.

                   2 moles of NH₄Cl produced  =  2 moles of NH₃

So,

              4.18 moles of NH₄Cl will produce  =  X moles of NH₃

Solving for X,

                     X =  4.18 mol × 2 mol / 2 mol

                     X  =  4.18 mol of NH₃

Step 4: <u>Calculate Percentage Yield as;</u>

             %age Yield  =  Actual Yield / Theoretical Yield × 100

             %age Yield  =  0.95 mol / 4.18 × 100

             %age Yield  =  22.72 %

5 0
3 years ago
3. The opening that allows light to enter the eye is the
xxMikexx [17]

Answer:

A)  Iris

Explanation:

The Iris controls the diameter of the opening in your eye, thus also controlling the amount of light let inside. It's also reponsible for the colour of you eye.

4 0
3 years ago
Read 2 more answers
What is the advantage of seeds that can be spread over a wide area?
Tema [17]

Answer:

I'm fairly sure it's D

Explanation:

If they're more spread out than they're roots in theory should have more space. Sorry if I'm wrong

6 0
3 years ago
Help me pls I put 49 point( every single point that I have) pls help me
Aliun [14]

Answer:

Chemical reaction, compound, molecule, covalent bonds, ionic bonds, ions. (first page)

Oxygen and hydrogen, 1 hydrogen 2 oxygen, H2O, a covalent bond, then mark off is always a liquid. (Second page)

Explanation:

6 0
3 years ago
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