Why does atomic radii decrease as you move from the left to right across the period

Answer:

If a compound is made from a metal and a non-metal, its bonding will be ionic. If a compound is made from two non-metals, its bonding will be covalent.

a.

The atomic radius of iridium is 1.355 Å

For a face-centered cubic unit cell, with edge length, a and atomic radius r,

we have a² + a² = (4r)²

2a² = 16r²

r² = a²/8

r = a/√8

Since a = 3.833 Å,

Substituting this into the equation, we have

r = a/√8

r = 3.833 Å/√8

r = 3.833 Å/2.828

r = 1.355 Å

So, the atomic radius of iridium is 1.355 Å

b.

The density of iridium metal is 22.67 g/cm³

To find the density of the iridium metal, we need to find the mass of atoms per unit cell.

So, for the face centered cubic iridium atom, there are 6 faces per unit cell × 1/2 atoms per face + 4 corners per unit cell × 1/4 atoms per corner = 3 atoms + 1 atom = 4 atoms per unit cell.

So, the mass of the atoms in the unit cell is m = number of atoms/cell × number of moles/atom × molar mass of Iridium

= 4 atoms/cell × 1 mol/6.022 × 10²³ atoms × 192.22 g/mol

= 768.88/6.022 × 10²³ g/cell

= 127.68 × 10⁻²³ g/cell

= 1.2768 × 10⁻²¹ g/cell

Next, we need to find the volume of the unit cell which is V = a³

= (3.833 Å)³

= (3.833 × 10⁻¹⁰ m)³

= 56.314 × 10⁻³⁰ m

= 5.6314 × 10⁻²⁹ m

So, the density of iridium = mass of unit cell/volume of unit cell

= m/V

= 1.2768 × 10⁻²¹ g/cell ÷ 5.6314 × 10⁻²⁹ m

= 0.2267 × 10⁸ g/m³

= 0.2267 × 10⁸ g/m³ × 10⁻⁶ m³/cm³

= 0.2267 × 10² g/cm³

= 22.67 g/cm³

So, the density of iridium metal is 22.67 g/cm³

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Answer:

20g

Explanation:

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Answer:

170 dm³ (2 significant figures)

Explanation:

CH₄ + 2O₂ → CO₂ + 2H₂O

We need to find how much 'volume' of O₂ is required to burn 56 g of CH₄.

Let's take the ratios of the two gases only.

CH₄ : 2O₂ (in terms of moles the ratio is 1:2)

56g : x dm³

Mr of CH₄ : Volume of oxygen at rtp

Find the Mr of CH₄.

Mr of CH₄ = 12 + (1 × 4) = 16

We know that 1 mole of any gas occupies 24 dm³ at room temperature and pressure (rtp). We have to find the volume of oxygen, there are 2 moles of oxygen, so 2 moles of gas will occupy:

2 × 24 = 48 dm³

56g : x dm³

  16 : 48 dm³

16x = 56 × 48

16x = 2688

x = [tex]\frac{2688}{16}[/tex]

x = 168 dm³

∴ the minimum volume of oxygen gas, at room temperature and pressure required to completely burn 56g of methane gas is 170 dm³

Answer:

hydrogen and helium is the answer.

the atomic mass of argon is 39.948. That means that one mole of argon weighs 39.948 grams (39.948 g/mol).

Answer:

2.4×1024 atoms.

Explanation:

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Answer:

1. Ethane has a higher boiling point

2. Heptyne has a higher boiling point

3. Octane has a higher boiling point

Explanation:

1. Ethane has stronger intermolecular attractions (van der Waal's forces) than ethene and so has the higher boiling point.

2. The longer (and the straighter) the chain, the greater the opportunity for intermolecular interactions, and thus the greater the boiling point. You should look up these boilig points! n-Pentane has a normal boiling point of approx. 36 ∘C ; n-heptane boils at 98 ∘C .

3. Octane has a high boiling point, because its molecule contains 8 Carbon atoms, and with increasing molecular weight of hydrocarbon its boiling temperature increases.

[tex]\huge \bf༆ Answer ༄[/tex]

The trends showing increase in ionization energy on the periodic table ~

[ due to increase in effective nuclear charge ]

[ Due to decrease in number of shells ]

Ionization energy increases across a period from left to right in the periodic  table.

Ionization energy is the energy needed for the complete removal of valence electrons in its ground state from an isolated atom in its gaseous phase at a specified temperature to form an ion.

Ionization energy shows periodicity in that it shows a regular variation across a period and down a group in the periodic table.

Ionization energy increases across a period from left to right in the periodic  table.

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Answer:

nothing

Explanation:

Answer:

Is there be suppose a file with this?

Explanation:

Answer:

Explanation:

Chemists categorize chemical changes into three main classes: inorganic chemical changes, organic chemical changes, and biochemical changes.

Burning of paper and log of wood.

Digestion of food.

Boiling an egg.

Chemical battery usage.

Electroplating a metal.

Baking a cake.

Milk going sour.

Various metabolic reactions that take place in the cells.

Answer:

The wavelength is 0.02 m.

Step-by-step explanation:

Given :

To Find :

Using Formula :

Apply Wavelength formula :

[tex]\star{\small{\underline{\boxed{\sf{\purple{\lambda = \dfrac{v}{f}}}}}}}[/tex]

Solution :

Finding the wavelength by substituting the values in the formula :

[tex]{\longrightarrow{\sf{\lambda = \dfrac{v}{f}}}}[/tex]

[tex]{\longrightarrow{\sf{\lambda = \dfrac{12}{600}}}}[/tex]

[tex]{\longrightarrow{\sf{\lambda = \dfrac{\cancel{12}}{\cancel{600}}}}}[/tex]

[tex]{\longrightarrow{\sf{\lambda = \dfrac{2}{100}}}}[/tex]

[tex]{\longrightarrow{\sf{\lambda = \cancel{\dfrac{2}{100}}}}}[/tex]

[tex]{\longrightarrow{\sf{\lambda = 0.02}}}[/tex]

[tex]\star{\underline{\boxed{\tt{\red{\lambda = 0.02 \: m}}}}}[/tex]

Hence, the wavelength is 0.02 m.

Answer:

2) To find the atoms from the moles, you just multiply Avogadro's number (6.02 x 10^23) by the moles.

So 3.35 x (6.02 x 10^23) = 2.0167 x 10^24 atoms are in 3.35 moles of aluminum

3) If the question is asking under standard temperature and pressure, we know that if we divide the volume by the molar volume of a gas (which is 22.7 in standard temperature and pressure), we can get the moles.  

So 101.25L / 22.7 = 4.46 mol

4) We know that to find the moles, it is the mass divided by the molar mass. If we rearrange the equation to solve for mass, we have to multiply the moles by the molar mass to get there.

Nitrogen's (N) molar mass on the periodic table is 14g/mol, but since Nitrogen is a diatomic element, it would be N2 by itself. So multiply 14 by 2, which will give you 28g/mol. N2's molar mass is 28g/mol.

Now you multiply 13.7 moles by 28g/mol, which will give you 383.6g

Just did a few edits here, 4.46 for question 3 is in moles not L

Taking into account the definition of avogadro's number,

2. 3.35 moles of aluminum contains 2.018ײ⁴ atoms.

3. 4.52 moles of CO₂ gas are in a 101.25 L container filled with CO₂ gas.

4. 13.7 moles of N₂ contain 383.6 grams.  

Avogadro's Number is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.

Then you can apply the following rule of three: if 1 mole of aluminum contains 6.023×10²³ atoms, then 3.35 moles of aluminum contains how many atoms?

amount of atoms of aluminum= (6.023×10²³ atoms × 3.35 moles)÷ 1 mole

amount of atoms of aluminum=2.018ײ⁴ atoms

Finally, 3.35 moles of aluminum contains 2.018ײ⁴ atoms.

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

Then, you can apply the following rule of three: If by definition of the STP conditions 1 mole of CO₂ occupies a volume of 22.4 L, how many moles does 101.25 L occupy?

[tex]amount of moles of CO_{2} =\frac{101.25 Lx1 mole of CO_{2} }{22.4 L}[/tex]

amount of moles of CO₂= 4.52 moles

4.52 moles of CO₂ gas are in a 101.25 L container filled with CO₂ gas.

The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.

In this case, the molar mass of N₂ is 28 g/mole. So, you can apply the following rule of three:  If 1 mole of N₂ contains 28 grams, 13.7 moles of N₂ contain how much mass?

[tex]mass=\frac{13.7 moles x28 grams}{1 mole}[/tex]

mass= 383.6 grams

13.7 moles of N₂ contain 383.6 grams.

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Answer:

its called Toxoplasmosis.

Explanation:

Cats become infected by Toxoplasma gondii by ingesting the cysts of this parasite. Most often, this occurs when cats eat mice or rats infected with the parasite. However, they can also ingest it during grooming after coming in contact with infected soil or feces.

hope it helped ;)

Archaea (Archaeon ): Single-celled microorganisms without nuclei and with membranes different from all other organisms. Once thought to be bacteria.

Unicellular organism

-A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Unicellular organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms.

Answer:

Ans:

*Carbohydrates

*Proteins

*Cholesterol

Explanation:

The plasma membrane is a structure that has several distinct roles in the cell

The plasma membrane is mainly composed of the phospholipid Bilayer, which is a layer of two sheets located in the internal and external parts. The Phospholipids are said to be Amphipathic because they have both properties of Hydrophobic and hydrophilic

*The Carbohydrate Molecules attach to the Plasma Membrane such as to the lipids and Proteins:

when They attach to the Proteins, they are known as glycoproteins, and they help in cell recognition, when they attach to the lipids, they are known as Glycolipids

*Protein Molecules play an important role in transport system such as Carrier Proteins

*Cholesterol Molecules help in balancing the Fluidity of the plasma membrane

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Answer:

I think you may have chosen the wrong subject for your question, besides where is the context to this?

Answer:

the answers are given in the photo

Answer:

15 mol

Explanation:

the balanced equation is AgNO3 + NaCl > NaNO3 + AgCl.

the stequiometry of the reactions says: one mol of silver nitrate reacts with one one mol of silver chloride to produce one mol of silver nitrate and one mol of sodium chloride.

by proportions, if you have 15 mol of AgNO3 you're gonna have 15 mol of AgCl

From 15 mol of Silver nitrate, the moles of silver chloride produced have been 15 mol. Thus, option B is correct.

The balanced chemical reaction for the synthesis of silver chloride has been:

[tex]\rm AgNO_3\;+\;NaCl\;\rightarrow\;AgCl\;+\;NaNO_3[/tex]

From the balanced equation, since there has presence equal moles of silver nitrate and sodium chloride, the moles of silver chloride formed has been equivalent. Thus, 1 mole of silver nitrate gives 1 mole of silver chloride.

The moles of silver nitrate available are,  [tex]\rm M_A_g_N_O_3=15\;mol[/tex]

The moles of silver nitrate produced can be given as:

[tex]\rm 1\;mol\;AgNO_3=1\;mol\;AgCl\\15\;mol\;AgNO_3=15\;\times\;1\;mol\;AgCl\\15\;mol\;AgNO_3=15\;mol\;AgCl[/tex]

Thus, the moles of silver chloride produced have been 15 mol. Thus, option B is correct.

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Answer:

B is correct.

Explanation:

A vaccination will trigger the organism to prepare antibodies as a measure of protection against a sickness.

Answer:

increase

Explanation:

Let's suppose we have a sample of air in a closed container. We heat the container and we want to predict what would happen to the pressure.

According to Gay-Lussac's law, the pressure of a gas is directly proportional to its absolute temperature.

Thus, if we increased the temperature of the air by heating it, its pressure would increase.

If a sample of air in a closed container was heated, the total pressure of the air would increase.

A 1.00 mole of Sulfuric acid (H₂SO₄) contains the largest number of atoms (7 atoms/molecule). Option B is correct.

To determine which of the given compounds contains the largest number of atoms in 1.00 mole, we need to consider the number of atoms in each compound.

1.00 mole of NH₃ contains:

1 mole of N atoms (1 atom/molecule)

3 moles of H atoms (3 atoms/molecule)

Total atoms = 1 + 3 = 4 atoms/molecule

1.00 mole of H₂SO₄ contains:

2 moles of H atoms (2 atoms/molecule)

1 mole of S atoms (1 atom/molecule)

4 moles of O atoms (4 atoms/molecule)

Total atoms = 2 + 1 + 4 = 7 atoms/molecule

1.00 mole of HBr contains:

1 mole of H atoms (1 atom/molecule)

1 mole of Br atoms (1 atom/molecule)

Total atoms = 1 + 1 = 2 atoms/molecule

Therefore, 1.00 mole of H₂SO₄, contains the largest number of atoms.

Hence, B. is the correct option.

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