Answer:
The radius of O^2- is 1.5*10^-8 cm and the radius of
Mg ^2+ is 6.2*10^-9 cm
Explanation:
Face centered cubic : 1/8 atoms on each edges + 1/2 atoms on each face
= [tex]\frac{1}{8}* 8 + \frac{1}{2}*6[/tex] = 4 effective atoms
MgO have a structure like NaCl forms a lattice of FCC.
density of the lattice = [tex]\frac{ z.M}{a^3*Na}[/tex]
z : no of atoms
M: mass of the atoms
a: radius of the atom
Na: Avogadro's number
a^3(radius) = [tex]\frac{ 4*40.3}{3.58*6.022*10^23}[/tex]
a^3 = 7.477 * 10^-23 cm^3
a = 4.21 * 10^-8 cm
Now calculating the anionic(ra O^2-) and cationic (rc Mg^2+)
in Fcc a = 2[tex]\sqrt{2} ra[/tex]
ra = 1.5*10^-8 cm
a = 2ra + 2rc
rc = a/2 -ra
rc = 6.2*10^-9 cm
The radius of O^2- is 1.5*10^-8 cm and the radius of Mg ^2+ is 6.2*10^-9 cm
Ammonium phosphate NH43PO4 is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid H3PO4 with liquid ammonia. Calculate the moles of ammonium phosphate produced by the reaction of 2.3mol of ammonia. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
0.767 moles of ammonium phosphate are produced
Explanation:
The reaction of ammona (NH3), with phosphoric acid is:
3 NH3 + H3PO4 → (NH4)3PO4
Where 3 moles of ammonia reacts per mole of H3PO4 to produce 1 mole of ammonium phosphate.
If 2.3 moles of ammonia reacts, the moles of ammonium phosphate produced if phosphoric acid is in excess are:
2.3 moles NH3 * (1 mole (NH4)3PO4 / 3 moles NH3) =
0.767 moles of ammonium phosphate are produced
Heat is a form of energy transfer from a blank location
Heat is a form of energy and transfer of it takes place from hotter body to cooler body.
What is heat transfer?Heat transfer is a process in which heat transfers from one object to another object without any loss.
Heat transfer is a branch of thermal engineering that deals with the production, use, conversion, and transfer of thermal energy between physical systems.
Transfer of heat generally takes place from hotter body to the cooler body till when both the bodies gain the same temperature.
Hence heat transfers from hotter body to cooler body.
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Which element has the lowest first ionization energy?
NEED ASAP
Select one:
a. 1s22s22p63s23p5
b. 1s22s1
c. 1s22s22p63s23p6
d. 1s22s22p63s1
Answer:
C
Explanation:
there is no explanation needed
Answer:
The value of ionization energy (IE) decreases down the group due to the increasing size as the valence electrons are more loosely bound. Thus lowest IE in this case is of Bi as it is bottom most element.
Explanation:
8. What do the results tell you about your hypothesis(es)?
Answer: Results will tell you which hypothesis is true.
Explanation: The hypothesis becomes a theory if the results support it. d.A new experiment is designed to provide additional data about the hypothesis. Imagine that a team of scientists test a certain hypothesis, and the experimental results show that it is false. ... The results will show which other hypotheses must be true.
A teacher is giving a lecture on the changes in world population over the last decade. Which is the best visual aid for
the teacher to use?
O a bar graph
O a map
• a line graph
O a diagram
Answer:
The correct answer would be C.) a line graph
Explanation:
I just did the assignment on edge 2020 and got it right
Please help me on question #2 please please really need help due today at 9:00pm please
Which of the compounds of H3PO4, Mg(OH)2, LiOH, and HCl, behave as acids when they are dissolved in water?A. Mg(OH)2 and LiOH.B. B H3PO4 and HC.C. Only HCl.D. Only LiOH.
Answer:
B. H3PO
Explanation:
The pH, texture, reactivity, and conductivity should be seen while determining acid or base. Among given option, H₃PO₄ is the acid when dissolved in water.
What are acid and base?Acid is a substance that has sour taste, pH lies in the range of 0-7 and give hydronium ion when dissolved in water. Acid turns blue litmus red. Whereas base has bitter, its pH is between 7-14 and it turns red litmus blue. It give hydroxide ion when dissolved in water.
Extensive properties, such as mass and volume depend on the amount of substance present and are not useful in the identification of a substance. Measuring mass and volume is not useful While determining acid or base. Out of given compounds, H₃PO₄ is the acid when dissolved in water.
Therefore, H₃PO₄ is the acid when dissolved in water.
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What force opposes the electromagnetic force in the atom?
Answer:
The strong forces oppose the electromagnetic force of repulsion between protons. Like ”glue” the strong force keeps the protons together to form the nucleus. The strong forces and electromagnetic forces both hold the atom together.
Explanation:
Hope This helps
Answer:
The strong forces oppose the electromagnetic force of repulsion between protons.
What is the change in internal energy (ΔΕ) of a system when 5 kJ of work is done on the system while it releases 13 kJ of energy to the surroundings?
The change in internal energy (ΔΕ) of a system : -8 kJ
Further explanationThe laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created
The equation is:
[tex]\tt \Delta U=Q+W[/tex]
Energy owned by the system is expressed as internal energy (U)
This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)
The sign rules for heat and work are set as follows:
• The system receives heat, Q +
• The system releases heat, Q -
• The system does work, W -
• the system accepts work, W +
5 kJ of work is done on the system : W = +5 kJ
releases 13 kJ of energy to the surroundings : Q = -13 kJ
[tex]\tt \Delta E=-13+5=-8~kJ[/tex]
how many neutrons make up one of these potassium atoms?
Answer:
20 Neutrons
Explanation:
The element of potassium has the symbol K. The nucleus of an atom of potassium contains 19 protons and 20 neutrons. I hope that answer helps xx
I need help click the image please help
Answer:
Answer:
a plant cell
Explanation:
because the chrolopast is green
Explanation:
How many grams of N2 are required to react with 2.30 moles of Mg in the following process? 3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)
Answer: 10.73 g
Explanation:
2.3 mol Mg * (1 mol N2 / 3 mol Mg) * (14 g Mg / 1 mol g) = 10.73
1. describe what difference if any there would be between the boiling point of alcohol measured in Houston and in Denver (the mile high city)
Answer:
See explanation
Explanation:
The boiling point of a substance at a location depends mostly on the atmospheric pressure in that location. The lower the atmospheric pressure in a location, the lower the boiling point and vice versa.
Boiling point is defined as the temperature at which the vapor pressure of the liquid becomes equal to the atmospheric pressure.
In Denver (the mile high city), alcohol will boil at a lower temperature(due to its high altitude) than in Houston because pressure decreases with height.
The boiling point of alcohol in Houston and Denver will vary as a result of the difference in atmospheric pressure.
The boiling point of a compound at a particular location depends on the
atmospheric pressure of that location. The lower the atmospheric pressure
of a given place or area, the lower the boiling point and vice versa.
In Denver (the mile high city), alcohol will boil at a lower temperature as a
result of its higher altitude than in Houston because atmospheric pressure
decreases with increase in height and vice versa.
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is a salt water solution saturated when there is undissolved salt at the bottom of the bottle?
Answer:
Yes
Explanation:
What is The compound with the formula SiCl4
Answer:
silicon tetrachloride or tetrachlorosilane
4)
Fluorine and element Z have similar chemical properties. Element Z could have an electron
configuration of
A)
2-2
B)
2-8-1
C)
2-8-8
D)
2-8-18-7
Answer:
D) 2.8.18.7
Explanation:
because it has 7 valence electron that occupied by shells
In which direction will the following equilibrium shift when solid sodium fluoride is added to an aqueous solution of acetic acid? CH3COOH â CH3COOâ + H+ A. The equilibrium shifts to the right, to form more products. B. The equilibrium shifts to the left, to form more reactants. C. There is no change; the system is still at equilibrium.
Answer:
A. The equilibrium shifts to the right, to form more products.
Explanation:
When sodium fluoride, NaF, is added to an aqueous solution, some HF is produced:
NaF + H₂O ⇄ OH⁻ + Na⁺ + HF.
That is, some H⁺ reacts decreasing its concentration.
Now, the equilibrium of the acetic acid is:
CH3COOH ⇄ CH3COO⁻ + H⁺
As the concentration of H⁺ decreases:
A. The equilibrium shifts to the right, to form more products.
In order to restore the initial equilibrium.
Classify H2O as cation, anion or neither
Answer:
H²O is neither a cation or anion
Explanation:
Hydrogen can form a cation (H+) or an anion (H-‐). Hydrogen in water (H20), ammonia (NH3), methane (CH4) and millions of other compounds is neither a cation nor an anion.
Are transition metals reactive?
Answer: Yes
Explanation:
These questions are from an experiment where we had a mixture of Ferrocene, acetylferrocene and diacetyl ferrocene and we separated each by using column chromatography. Before doing the column chromatography we did TLC analysis to ensure that we did, in fact, have a mixture of these 3 compounds.
During the column chromatography we first eluted the ferrocene using pure hexane. Then we eluted the acetylferrocene using a 1:1 mixture of hexane and methylene chloride. Then we eluted the diacetylferrocene using a 9:1 mixture of hexane and methylene chloride.
1. Rank ferrocene, acetylferrocene, and diacetylferrocene in order of increasing polarity. Do the TLC results from your fractions support this ranking? Explain.
2. Rank the solvents used in the experiment in order of increasing polarity.
3. Why do you start with the least polar solvent/solvent mixture and progress to increasing polar solvent/solvent mixtures when eluting the ferrocene compounds from the column rather than starting with more polar solvent system and progressing to less polar solvents?
4. How do the thin layer and column chromatography for this experiment compare in regard to stationary and mobile phases?
5. What key feature in the IR spectrum of acetylferrocene distinguishes it from the spectrum of ferrocene?
Answer:
Explanation:
The polarity of the 3 compounds would be in the order of
Ferrocene < Acetylferrocene < Diacetylferrocene
Your TLC data has to also support this observation . This can be checked by measuring the values of Rf ( Retention factor = distance travelled by solute/solvent ) .The Rf values also has to follow this particular order: -
Ferrocene > acetylferrocene > diacetylferrocene
2) Hexane happens to be a non-polar solvent. The polarity of hexane can be increased if some polar solvents for example, ethyl and methylene chloride etc are added
Therefore, in the increasing order of solvents polarity, we have
Hexane < 1:1 mixture of hexane: methylene chloride < 9:1 mixture of methylene chloride:
3) Chromatographic techniques all have a stationary phase in addition to a mobile phase. In the case of column chromatography, the silica gel will be the stationary phase and the solvent that will be poured will be the mobile phase.
4) The TLC and column chromatography both happen to have the same stationary phase which is the silica gel. Also, the same solvent mixture is used in both the techniques. This makes the result of the 2 to be almost the same. The difference seen between them is that, TLC works against the gravity while on the other hand column chromatography works in the direction of the gravity.
5) The key feature in the IR spectra of the acetylferrocene that will be absent in the spectra of ferrocene is the presence of carbonyl stretching frequency at close to 1700 per cm(cm-1). This peak is easily differentiated between both acetyl ferrocene and ferrocene.
A mixture of two gases with a total pressure of 2.00 atm contains 0.70 atm of Gas A. What is the partial pressure of Gas B in atm?
The partial pressure of Gas B : 1.3 atm
Further explanationDalton's Law stated
the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
Can be formulated:
[tex]\tt P~tot=P1+P2+P3...Pn[/tex]
P tot = 2 atm
P gas A = 0.7 atm
So P gas B :
[tex]\tt P~gas~B=P~tot-P~gas~A\\\\P~gas~B=2-0.7=1.3~atm[/tex]
The partial pressure of Gas B in the mixture of two gases has been 1.3 atm.
The partial pressure of the gas can be defined as the pressure of the particular gas in the mixture of gases.
According to dalton, the total pressure of the gas has been the sum of the partial pressure of the individual gases.
Thus, total pressure = partial pressure of gas A + partial pressure of gas B
Given, total pressure = 2 atm
The partial pressure of gas A = 0.70 atm
So, the partial pressure of Gas B = total pressure - partial pressure of gas A
The partial pressure of Gas B = 2.0 atm - 0.70 atm
The partial pressure of Gas B = 1.3 atm
Thus, the partial pressure of Gas B in the mixture of two gases has been 1.3 atm.
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A gas sample has a gas density of 5.95 g/L at 100°C and 755 mmHg. Determine the molar mass of the gas.
Answer:
M = 184.1 g/mol
Explanation:
Given data:
Density = 5.95 g/L
Temperature = 100°C (100+273 = 373 K)
Pressure = 755 mmHg = (755/760 = 0.99 atm )
Molar mass of gas = ?
Formula:
d = PM/RT
Solution:
M = dRT / P
M = 5.95 g/L × 0.0821 atm.L/mol.K × 373 K/ 0.99 atm
M = 182.21atm.g/mol / 0.99 atm
M = 184.1 g/mol
The brain combines the electrical signals sent from the what? I NEED THIS ASAP PLEASE!!
Unit Test Unit Test Active 13 TIME REMAINING 01:31:26 Chemical A and Chemical B react in an exothermic reaction. What can be known about what will happen when Chemical A and Chemical B are mixed together? O The new substance will need more energy to form its chemical bonds than the old substance will release. More energy will be released from the old substance than the new substance will need to form its chemical bonds. The color will change as a result of the reaction. O The substance will bubble as a result of the reaction. Save and Exit Next Submit Mark this and return
Answer:
More energy is released from the old substance than the new substance needs to form its chemical bonds
Explanation:
Chemical A and Chemical B react in an exothermic reaction. When Chemical A and Chemical B are mixed together more energy will be released from the old substance than the new substance will need to form its chemical bonds. Therefore, option B is correct.
What is an exothermic reaction ?When a chemical reaction goes on, energy is shifted to or from the surroundings. When energy is moved to the surroundings, this is called an exothermic reaction, and the temperature of the surroundings increases.
Examples of exothermic reactions are combustion reactions and many oxidation reactions.
A chemical reaction is exothermic if heat is passed by the system into the surroundings. Because the surroundings are deriving heat from the system, the temperature of the surroundings increases.
Thus, option B is correct.
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How is the charge found in an element?
Answer:
Positive charge if there are more protons than electrons. Negative charge if there are more electrons than protons. If there's the same amount of protons and electrons, it's a neutral charge.
Explanation:
All matter is made up of electrons and protons. Electrons have a negative charge, protons have a positive charge. A charge is a type of particle measurement, and it is determined based on the amount of protons or electrons in a certain thing. The charge is which one there are more of, and there’s no charge (neutral) if they’re balanced.
Select all possible answers:
Which statement(s) are true about valence electrons?
a. Atoms are very reactive when they have full valence energy levels.
b. Atoms readily lose or gain valence electrons in order to achieve a full
outer energy level.
c. Atoms are stable when they have as many valence electrons as possible.
d. Valence electrons determine many of the properties of an atom.
Answer:
c and d are correct
Explanation:
In A, false because in Valence Electrons, the more the valences, the more stable an atom is.
In B, false because atoms cannot readily gain or lose valence electrons as the number of valence electrons is determined by the column they are in.
In C, true because the more the valence electrons, the more the stability of an atom.
In D, true as electron placing is important and the reactivity of an atom is important.
So C and D are true!
The statement(s) which are true about valence electrons are:
c. Atoms are stable when they have as many valence electrons as possible.
d. Valence electrons determine many of the properties of an atom.
An atom refers to the smallest, indivisible unit that isnmade up of matter and forms all chemical elements.
In Chemistry, an atom comprises three (3) distinct particles and these are;
Protons. Neutrons. Electrons.Valence electrons is simply the number of electrons that is/are present in the outermost shell of the atom of a chemical element.
Generally, valence electrons are typically used to determine whether an atom or group of chemical elements can bond with other chemical elements.
As a general rule, atoms with as many valence electrons as possible are more stable and reaches an octet state.
Lastly, valence electrons are used to determine the chemical properties of of the atom of a chemical element.
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Read the information about the halogen family.
Elements within a group share similar properties. Elements in the halogen family, such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), all have seven valence electrons. Iodine is an important element for human health. The thyroid gland uses iodine to produce hormones. One of the hormones it makes is a covalent compound called thyroxine.
Given this information, what effect do you think other halogen elements have on human health? State your prediction, and do some research on one of the halogen elements to see how it affects human health. List your findings, and then give your opinion on whether you think the element you chose should be used in food products, cleaning products, or in other manners that cause it to come in contact with humans. Be sure to provide evidence from your research to support your opinion.
Answer:
See explanation
Explanation:
Chlorine is a member of the halogen family known as a toxic yellowish green gas. Inhalation of chlorine for a prolonged period of time leads to pulmonary edema. If a person comes in contact with compressed liquid chlorine the person may experience frostbite of the skin and eyes.
However chlorine is very useful in water disinfection and is preferred in water treatment because it provides residual disinfection of the treated water.
Chlorine gas may be dissolved in NaOH to form oxochlorate I which is used as a bleach in cleaning.
Answer:
Iodine
Explanation:
iodine is pretty good for you in moderation, iodine can ensure proper tyriod function but too much of it can cause thyroid gland inflammation and thyroid cancer, burning of the mouth, throat, and stomach; and coma.
s this statement true or false? All worms belong to the same phylum.
Answer:
FALSE.
Explanation:
The right answer is false. There are three different groups of phylum for worms.
Hope this helped!
Answer:
FALSE
there are like 3 different phylum
Explanation:
Hope this helps!
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Why is the following electron configuration not possible?
1-9-1
Answer: because its noy
Explanation:
Larry was told that a certain muscle cream was the newest best thing on the market and claims to double a person’s muscle power when used as part of a muscle-building workout. Interested in this product, he buys the special muscle cream and recruits Patrick and SpongeBob to help him with an experiment. Larry develops a special marshmallow weight-lifting program for Patrick and SpongeBob. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Patrick’s arms and back are lathered in the muscle cream, while Sponge Bob’s arms and back are lathered with the regular lotion.
Which person is the control group?
SpongeBob
SpongeBob
Patrick
Patrick
Larry