Answer:
The correct option is;
d) LiF
Explanation:
The Lattice energy of ionic compounds can be calculated using the modified Coulomb's law as follows;
[tex]U = \dfrac{k' \cdot Q_1\cdot Q_2}{r_0}[/tex]
Where;
Q₁ and Q₂ = The ionic charges
k' = A constant depending on the ionic and valence configuration
r₀ = The distance between the two nucleus
Given the four compounds each of the metallic ions are of the same group (group one) have the same (only one) valence electron, and are combined to the same ion (fluoride ion) such that Q₂, is the same for all compounds, the factor that will influence the lattice energy more will be the r₀
The sizes of the atoms Li, Na, K and Cs increases as arranged as such Li has the least r₀, and therefore LiF the least lattice energy
From chemistry test online, we have;
The lattice energy of LiF = -1045 kJ/mole
The lattice energy of NaF = -924 kJ/mole
The lattice energy of KF = -822 kJ/mole
The lattice energy of CsF = -737 kJ/mole.
Which best describes the importance of the microscope to the development of the cell theory?
Answer:
The answer is "all the cells are too small, which is not seen by the naked eye, that's why we use a microscope to see it".
Explanation:
In the given question the choices were missing so, we define the correct answer only.
Cells are the essential building blocks of all living entities. There will be trillions of cells within the body. They construct a body shape, absorb nutrients, transform them into energy, and conduct specialized features.
It provides stability and guidance, encourages mitotic cell development, encourages active and passive transfer, generates energy, induces metabolic processes, and contraceptive support.
Express each of the following in standard form.
3.6 x 101
6.452 x 102
8.77 x 10-1
6.4 x 10-3
Answer:3.6 x 101 or 8.77 x 10-1
Give two examples of neutralization
Answer:examples for neutralization - treating indigestion,treatment for insect bites.hope it help you
Explanation:
which state of matter is Na OH(s)
Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
Define freezing....... Correct and detailed answers will be marked as Brainliest.
The transformation of liquid into solid when it reaches when it's temperature is below freezing point.
Answer:
Freezing:
When liquid is converted to solid, the process is called freezing.
Conditions for freezing:
1) Temperature must be lowered.
2) The temperature should be below 0 degree centigrade.
Example:
The conversion of "liquid water" into "ice".
=> We can use a "freezer" to freeze things.
3. why are fire tornadoes rare ?
absorption of digested food takes place in the
Answer:
Explanation:
Absorption of digested food takes place in the small intestine.
Hope this helps
plz mark as brainliest!!!!!
Answer:
Absorption of digested food takes place in the small intestine.
Explanation:
What is the molarity of a 50.0ml aqueous solution containing 10.0 grams of hydrogen peroxide H2O2
Molarity= No of moles of solute * 1000 / vol solution in ml
No of moles= Given mass / Molar mass
Given Mass of solute (H2O2)= 10g
Molar mass of H2O2=34gmol^-1
No of moles= 10/34= 0.294 moles
Volume of solution=50ml
Molarity = 0.294*1000 / 50
Molarity = 5.8M
In science class, Jake mixed water with differing amounts of an unknown liquid. After mixing the liquids, he heated 20 milliliters (ml) of each mixture and observed how quickly it boiled. The table shows his results.
According to the question, each mixture decrease the boiling point of the water.
What is boiling point ?Boiling temperature is defined as the temperature at which liquid change into a vapour at the atmospheric pressure at sea or ocean level.
For example the boiling temperature of water is 100 degree celcius.
Thus, each mixture decrease the boiling point of the water, option "A" is correct.
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what’s the answer to this?
The table describes how some substances were formed.
Substance
P.
Q
Description
Formed by boiling pure water
Formed by combining three hydrogen atoms to every nitrogen atom
Formed by adding 5 g of sugar to 1 L of water
Formed by compressing carbon under high pressure
R
S
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Explanation:
Which is a pure substance?
1. soda
2. gasoline
3. salt water
4. carbon dioxide
carbon dioxide
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of -7.2°C. Bromine can be classified as a
1. compound.
2. impure substance.
3. mixture.
4. pure substance.
pure substance.
Answer:
the answer is
Explanation:
Sugar and water make a homogeneous mixture (the same proportions of its components throughout any given sample).
Which are the physical properties of water
HELP PLEASE NAME THESE COMPOUNDS topic of amines and amides please explain you steps so i can do the rest of the problems myself
The attachment shows the diagram of two molecules respectively;
The first molecule in the attachment is known as triethylamine,The functional group is amine Which is - CONH2
And there is a methyl group as an attachment, attached at the third(3) carbon atom,making the compound triethyamine.
The second molecule in the attachment is an example of a secondary amide.
The longest carbon chain is five which pentanamide.
The functional group is amide.
The compoud is named by replacing the suffix - ane in pentane (alkane) to the suffix - amide.
Making the compound pentanamide.
In the image above the ruler is measuring in centimeters. The blue cylinder falls somewhere between 2.7cm and 2.8cm according to the ruler. Since we can estimate the last digit I would say that the length of the cylinder is 2.76cm. Since I am estimating any number 2.72cm or 2.78cm could also be correct.
Why would 2.755 not be a correct measurement according to estimating the last digit?
Answer:
The answer is below
Explanation:
Resolution is the smallest unit of measurement that can be measured by a measuring instrument. Each point on the ruler is 0.1 cm and the difference between any two points, about 0.01 cm cam be measured. The minimum measurement (resolution) that can be measured by the ruler is 0.01 cm (two decimals), therefore it cannot measure up to three decimal places such as numbers like 2.755.
what is the correct electron configuration for an element with five electrons in the third energy level
[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.
What are elements?Elements are the simplest substances which cannot be broken down using chemical methods.
The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.
The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries 32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.
The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
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Questions
1 Explain why a solid expands when it is heated.
2 Explain how the liquid in a thermometer changes so that it can be used to
measure a temperature.
3 Use particle theory to explain why solids and liquids cannot be compressed
(squashed into a smaller volume).
4 Use particle theory to explain why liquids and gases can flow.
Answer:
answer of question 1 is
Explanation:
solids are denser than liquid and gases because solid particles are closely packed and do not have any empty spaces between their particels so when solid will heated its particles will spread and there will have more spaces between them so a solid expand on heating.
What is atom economy? A. All of these B. The system that determines how much 1 mole of a pure element costs. C. The measure of how much of the reactants end up as products in a chemical reaction. D. The system of exchanging electrons that occurs in atoms.
Answer:
C
Explanation:
It's the amount of products you get compared to all the reactants you use. It's kind of like economy in that it's profit, and the higher the atom economy the more products/profit you have.
Answer:
C.) The measure of how much of the reactants end up as products in a chemical reaction.
Explanation:
I got it right on founders edtell.
5. What distinguishes the noble gases from other elements in the main group?
How does this contribute to the tendency for the various elements to react
with each other?
Answer:
Noble gases are the least reactive of all known elements. Their outer energy levels are full because they each have eight valence electrons. ... As a result, noble gases cannot become more stable by reacting with other elements and gaining or losing valence electrons.
Explanation:
Noble gases have complete valence shells so they do not participate in the reactions while the other elements in the main group have incomplete valence shells so they participate in the reaction to complete it.
What are noble gases?Noble gases can be described as the six elements that belong to the 18th group of the modern periodic table. The elements of group 18 are Helium, Neon, Argon, Krypton, Xenon, and Radon.
Under normal temperature and pressure conditions, all noble gases exist in the gaseous state and exhibit low chemical reactivity hence they are also referred to as inert gas. All noble gases possess stable electronic configurations because their valence shell is fully filled.
Noble gases are generally found as mono-atomic gases. The general electronic configuration group 18 elements can be written as ‘ns²np⁶’ where n is the principal quantum number.
Therefore, the reactivity of the noble gases can be distinguished from other elements in the main group.
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Why are ionic crystals soluble in water?
A. The covalent bonds in the ionic crystal can easily reshape to bond with the water molecules, allowing it to dissolve.
B. The water slides the layers of the ionic crystal lattice so that positive charges line up with positive charges. They repel
each other and break the crystal apart.
C. Partial charges in water molecules attract the charges in the atoms of the ionic crystal, pulling the atoms off the crystal.
D. They are not. The positive and negative charges in the ionic lattice are stronger than the partial charges in the water.
Answer:
C. Partial charges in water molecules attract the charges in the atoms of the ionic crystal, pulling the atoms off the crystal.
Explanation:
Water consists of partial positive and hydrogen ions and partial negative oxygen ions. The ionic crystals also dissociate into ions when in water.These partial charges and ability of ionic compounds to dissociate in water are the main reason why ionic crystals dissolve in water.
The partial charges in the water molecules form a strong attraction towards the charges in the atoms of ionic crystals. This then pulls the atoms from the crystals and ends up in the dissolution of the ionic crystals.
what are the efficient things needed for a village
Answer:
Those aspects which are something a village needs are specified beneath.
Explanation:
Things being equally necessary to make living simpler and therefore more enjoyable. The government has promised to continue providing basic facilities to either an unpopulated location, including such roads, drinkable water, as well as electric power. Therefore, throughout the village, certain things accessible with maximum variety and quality that have become the basic requirements for this human existence.Sulphur dioxide is a common pollutant from burning coal.State two effects caused by this pollutant and also write the chemical equation.
Heya!
Sulfur dioxide - ( SO2 )
Answer:
Sulfur dioxide is a common pollutant caused due to the burning of coal,Is very harmful for the environment and health.Effects:
Health effects-Sulfur dioxide effects the respiratory system which includes the functioning of lungs,respiratory track and causes infections,can also effect and irritate the eyes and causes aggravating conditions such as asthma and chronic bronchitis.As most sulfur dioxide air pollution comes from the burning of coal and oil in power plants. It is a emitted by trains, large ships and other diesel objects that burns alota sulfur fuel so this also effects the environment like plants and others as the air lacks oxygen ,but with more sulfur dioxide.Hope this helps!
Have a nice day!:)
which of the following is a scientific question about the cuttlefish?
Answer:
How does the cuddle fish change its colors?
Please tell me if I'm wrong.
differences between properties of convalent and ionic bond.
Ionic bonds will be a metal + a nonmetal, and electrons
are transferred from the metal to the nonmetal.
A covalent bond will be a nonmetal only. Nonmetals will not give up their electrons so electrons are shared.
I have also written this on the whiteboard in the image provided.
All the simple machines make work easier to do by changing the _____ or _____ of a force. A. size; type B. work; type C. size; direction D. type; direction
Answer:
C. size; direction
Explanation:
By definition, a machine is referred to any device that makes work easier. It takes force to do work, hence, work refers to the application of force over a particular distance. A machine aims at making the work easy by changing how it is done. Simple machines, which include: levers, pulleys, inclined planes etc. all carry out the same thing, which is to make work easier, by changing the size/magnitude and direction of the applied force.
A simple machine tends to change the size of the inputted force by increasing it over a shorter distance. The machine increases the force applied better than it can be done manually e.g. a plier and nutcracker increases/changes the applied force better than it can be done with bare hands.
Also, a simple machine can achieve making work easier by changing the direction at which the force is applied. The machine applies the force on the object in an opposite direction or contrary to the way it was manually applied.
Write down the dissolution equation for nickel(II) perchlorate dissolving in water. (Perchlorate is a polyatomic ion with the formula ClO41-.) If four moles of the ionic compound are dissolved, then how many moles of the ANION are present in the solution?
Answer:
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
8 mol ClO₄⁻
Explanation:
Let's consider the dissolution equation for nickel(II) perchlorate dissolving in water.
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
The molar ratio of Ni(ClO₄)₂ to ClO₄⁻ is 1:2. If 4 moles of Ni(ClO₄)₂ are dissolved, the moles of ClO₄⁻ formed are:
4 mol Ni(ClO₄)₂ × (2 mol ClO₄⁻/ 1 mol Ni(ClO₄)₂) = 8 mol ClO₄⁻
Please be I need this quick
2. For each pair of atoms determine which can steal an electron easier (higher electronegativity),
draw a picture of Bohr's model, and explain why:
a. Oxygen and Fluorine
b. Sodium and Potassium
c. Boron and Calcium
Answer: Option (A) is the correct answer.
Explanation:
An atom who has seven valence electrons in its ground state will have the following electronic configuration in its sub shells as 2, 7.
Thus, there will be in total 9 electrons and it is known that fluorine has atomic number 9.
Whereas sodium has 2, 8, 1 electrons in its sub-shell.
Calcium has 2, 8, 8, 2 electrons in its sub-shell and oxygen has 2, 6 electrons in its sub-shell.
Thus, we can conclude that out of the given options, fluorine is the element whose atom in the ground state has seven valence electrons.
4. The mass of a silver liberty (coin) was measured three times and each measurement was made
to five digits. The mass values were 12.519 9.12.521 g, and 12.496 g. The average mass was
reported as 12.512 g.
Why is the average mass of the gold coin reported to five significant figures, even though you
had to divide by "3" to obtain the average?
Answer:
The average mass of the gold coin reported to five significant figures, even though you had to divide by "3" to obtain the average.
Explanation:
Given that,
The mass of a silver liberty was measured three times and each measurement was made to five digits.
The mass values are,
[tex]m_{1}=12.519\ g[/tex]
[tex]m_{2}=12.521\ g[/tex]
[tex]m_{3}=12.496\ g[/tex]
The average mass of the gold coin is 12.512 g.
We know that,
Significant figures :
Significant figures is explained the nonzero, leading zero and zeros between two nonzero digits.
For example,
The digits is 0.003405
In the digit, 345 = nonzero
0.00 = leading zero
The average mass of the gold coin reported to five significant figures because average mass is 12,512. All digits are nonzero.
Nonzero digit are significant.
Hence, The average mass of the gold coin reported to five significant figures, even though you had to divide by "3" to obtain the average.
Draw the geometric, linkage, and ionization isomers for [CoCl5CN][CN].
Answer:
See explanation
Explanation:
The formation of isomers is common to octahedral complexes. Isomers are different compounds with the same molecular formula but different structural formulas. Isomers have different atom to atom connections. Werner's complexes can display; polymerization, ionization, linkage, geometric and optical isomerism among others.
Isomers of coordination compounds are not easily recognizable and not easily separable in the laboratory.
The geometric, linkage and ionization isomers of the complex given in the question are shown below.
One day, you decide to pop some popcorn. You put the bag in the microwave, but after a couple of minutes of cooking it is clear the popcorn is not popping. Why did this happen? What steps could you take to help locate the problem?
Di- Ethyl zinc is a chemical used in the library to protect books from worms, its composition is 53% Zinc, 38.9% Carbon, and 8.1% Hydrogen (At mass of Zn=65.4, C=12, H=1). Find the empirical formula of a compound
Answer:
ZnC4H10
Explanation:
The empirical formula of a compound refers to the formula that gives the simplest whole number ratio of each atoms of the elements in the compound.
The empirical formula is calculated thus:
The given percentages in the question represent the mass in grams of each element in the compound.
Zinc= 53%, C= 38.9%, H= 8.1% which represents 53g, 38.9g and 8.1g of each element respectively.
Molar Mass of Zn= 65.4 g/mol
Molar Mass of C= 12 g/mol
Molar Mass of H= 1 g/mol
Step 1: Divide the mass of each element by the molar mass given to convert to moles:
Zn= 53/65.4 = 0.81moles
C= 38.9/12 = 3.24moles
H= 8.1/1 = 8.1moles
Step 2: Divide each mole value by the smallest number of moles calculated, which is 0.81moles:
Zn= 0.81/0.81 = 1
C= 3.24/0.81 = 4
H= 8.1/0.81= 10
This is the mole ratio represented in the subscript of each element in the empirical formula:
That is, Zn (1) C (4) H (10)
Empirical formula= ZnC4H10
