Iridium crystallizes in a face-centered cubic unit cell that has an edge length of 3.833 Å.
(a) Calculate the atomic radius of an iridium atom.
(b) Calculate the density of iridium metal
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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Through meiosis and sexual reproduction, children that are produced from parents are almost
guaranteed to be unique. Explain how events in meiosis and reproducing through sexual reproduction dramatically increase the genetic variability of a person.
Answer:
Mitosis: Cell division in Asexual Reproduction. 2 Daughter cells exactly like the parent. Heredity is passed to offspring: 100% DNA from 1 parent. Meiosis: Cell division in Sex Cells during Sexual Reproduction.
Explanation:
A 12.17 g sample of a compound contains 7.77 g of iron, Fe, 1.44 g of phosphorus, P, and oxygen, O. Calculate the empirical formula for the compound.
Answer:
Fe₃PO₄
Explanation:
They have given the total mass of the compound, the mass of iron and the mass of phosphorus. So we can find the mass of oxygen.
Mass of oxygen = 12.17 - (7.77 + 1.44) = 2.96g
So we can now find the empirical formula.
Element - mass - Mr - Mass÷Mr - Ratio - Simplest Ratio
Fe - 7.77g - 55.8 - [7.77÷55.8] - [0.14÷0.05] - 2.8 = 3
P - 1.44g - 31 - [1.44÷31] - [0.05÷0.05] - 1
O - 2.96g - 16 - [2.96÷16] - [0.19÷0.05] - 3.8 = 4
[The simplest ratio was obtained by dividing the answer of mass÷mr with the smallest value. Phosphorus had the smallest value of mass÷mr=0.05, so all other answer were divided by 0.05]
Emperical formula = Fe₃PO₄
The main-group elements are the forty-four elements that occupy groups 1A-8A of the periodic table. Main-group elements are important because of their high natural abundance both in the Earth's crust and in the human body and are commercially valuable. Review the families containing main group elements. Identify all the characteristics that apply to the elements in family IA.
Answer:
The answer is a,b, and c. This is for the USA tesprep videos
Explanation:
The characteristics that apply to the elements in the family are they are highly reactive, they are shiny, soft metals and the element form +1 ions when forming compounds. Thus option a, b and c is correct.
What are main group elements?Main group elements are defined as any of the element belonging to the s and p blocks of the periodic table.
They are most abundant element in universe and on earth.
This elements and their compound are one of the most important economical elements.
They are very good conductor of heat and electricity.
Thus, the characteristics that apply to the elements in the family are they are highly reactive, they are shiny, soft metals and the element form +1 ions when forming compounds. Thus option a, b and c is correct.
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what can cats get from eating mice and moles?
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.
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Which of the following compounds contains the largest number of atoms? *
O A. 1.00 mole of NH3
O B. 1.00 mole of H2SO4
о
C. 1.00 mole of HBr
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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How did the believers show their fellowship with one another?
Answer:
I think you may have chosen the wrong subject for your question, besides where is the context to this?
How can one determine if a compound is ionic or covalent?
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.
50 POINTS PLEASE HELPP
Circle the compound that has the higher boiling point and explain why we see the
differences we do
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.
If the velocity of a wave is 12 m/s and its frequency is 600 hertz, what would be its wavelength?
Answer:
The wavelength is 0.02 m.
Step-by-step explanation:
Given :
[tex]\green\star[/tex] Velocity = 12 m/s[tex]\green\star[/tex] Frequency = 600 HzTo Find :
[tex]\green\star[/tex] WavelengthUsing Formula :
Apply Wavelength formula :
[tex]\star{\small{\underline{\boxed{\sf{\purple{\lambda = \dfrac{v}{f}}}}}}}[/tex]
[tex]\pink\star[/tex] λ = Wavelength [tex]\pink\star[/tex] v = Velocity [tex]\pink\star[/tex] f = FrequencySolution :
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.
If a sample of air in a school container was heated, would the percentage of oxygen in the air increase, decrease, or remain unchanged?
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.
Calculate the minimum volume of oxygen gas, at room temperature and pressure(r.t.p). required to completely burn 56g of methane gas. Give your answer to two significant figures. (1 mole of any gas occupies 24 dm³ at r.t.p,Ar:C=12,H=1)
BALANCED EQUATION FOR THE BURNING OF METHANE GAS.
CH₄+2O₂→CO₂+2H₂O
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
Which term describes the small, somewhat circular pattern of wind?
A Easterlies
B Trade Winds
C polar winds
D convection cells
Answer:
its D, convection cells
Look at the diagram. Which shows the correct arrangement of electrons in a hydrogen chloride molecule?
Answer:
D............................
There are two types of chemical compound one is covalent compound and another is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. The correct representation is option D.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
Covalent bond is present in molecule HCl. Hydrogen has 1 electron in its outermost shell. Chlorine has 7 electrons in its valence shell. So one one electron from each element is shared between them to form a covalent bond.
Therefore, the correct representation of arrangement of electrons in a hydrogen chloride molecule is option D.
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1. Have scientists been able to invent a perpetual motion machine?
O Yes
O No
The reaction below shows how silver chloride can be synthesized. AgNO3 NaCl Right arrow. NaNO3 AgCl How many moles of silver chloride are produced from 15. 0 mol of silver nitrate? 1. 0 mol 15. 0 mol 30. 0 mol 45. 0 mol.
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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What can move from energy level to energy levels when it gains or loses what
Answer:
nothing
Explanation:
Which statement concerning simple sugars and amino acids is correct
Answer:
Is there be suppose a file with this?
Explanation:
what are the three molecules that are attached to the plasma membrane, and what are their roles/ functions?
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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how many moles are there in 1 mole of argon?
the atomic mass of argon is 39.948. That means that one mole of argon weighs 39.948 grams (39.948 g/mol).
23. An organism develops active immunity as a result of
A) manufacturing its own antigens
B) producing antibodies in response to a
vaccination
C) receiving an injection of antibodies produced
by another organism
D) receiving an injection of a dilute glucose
solution
a
Answer:
B is correct.
Explanation:
A vaccination will trigger the organism to prepare antibodies as a measure of protection against a sickness.
What chemical processes are involved in chemistry? I need 3+ chemical changes that occur during the chemistry process..
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.
When water changes state from solid to liquid to gas, ALL BUT one thing happens. There is no
A) chemical change.
B) physical change.
C) addition of energy.
D) increase in temperature.
what is the number of the atom in 1 mole of methanol CHɜOH ?
should i tell my parents i got C+ in chemistry or not ?
How many moles are in 34.6 g of sulfur oxide (SO)?
a scientist finds an organism that has a single cell without a nucleus.This organism was found in pond water.In which KINGDOM douse it belong?if you can explain
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.
What is released when a bond between two atoms breaks?
A. Electrical energy
B. Chemical energy
C. Intermolecular force
D. Intramolecular force
how does ionization energy increase on the periodic table
[tex]\huge \bf༆ Answer ༄[/tex]
The trends showing increase in ionization energy on the periodic table ~
Ionization energy increases as we move from left to right in a period.[ due to increase in effective nuclear charge ]
Ionization energy increases as we move from bottom to top in a group.[ Due to decrease in number of shells ]
Ionization energy increases across a period from left to right in the periodic table.
Ionization energyIonization 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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How many atoms are in 11.5g of Hg