Which statement best describes what occurs to the valence electrons in a CH4 molecule during hybridization
Answer:
The orbitals on the carbon atom are hybridized; the bonds result from overlap of carbon hybrid orbitals with hydrogen atomic orbitals
Explanation:
In the formation of methane, carbon atoms are sp3 hybridized. One s orbital in carbon mixes with three p orbitals of carbon to yield a set of four sp3 orbitals which bonds to four hydrogen 1s orbitals by sigma bonds.
The molecule is tetrahedral with a bond angle of 109.5 degrees
Which of the following statements is true during a solar eclipse?
The moon's light is blocked by the Earth.
The Sun's light is blocked by the Earth.
The Sun's light is blocked from another planet.
The Sun's light is blocked by the Moon.
Answer:
The sun's light is blocked by the moon.
Explanation:
During the eclipse, the moon rotates right in front of the sun, that's why the eclipse is so rare and only happens every four(?) years/
Why do silver and copper have similar properties? (science CER)
Answer:Copper is a chemical element with the atomic number 29, and the chemical symbol Cu. Silver is also found on the periodic chart of elements, and has a chemical symbol of Ag and an atomic number of 47.
Explanation:
Both silver and copper are transition metals of d-block in periodic table they are in the same group and thus shows similar chemical and physical properties.
What is group in periodic table?In periodic table, elements are classified into groups and periods. The horizontal rows are called periods and the vertical columns are called groups.
There are 18 groups and 7 periods in periodic table. Elements of the same group have same number of valence electrons and similar chemical and physical properties.
Silver, copper and gold are in 11th group of periodic table. Thus they have 9 valence electrons and exhibit similarity in properties. All these metals are good conductors and are used in electrical and optoelectronic devices.
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Which of these changes occurs by the removal of energy
HELP!! Please answer!
Answer: the % is 99.73 and the mass is 40.986
Explanation:
What happens when the sound waves released by a bat hit an object?
O The sound waves are diffused.
O The sound waves are reflected.
O The sound waves are refracted.
O The sound waves are absorbed.
Answer:
O The sound waves are reflected.
Explanation:
When sound waves released by a bat hits an object, the sound waves are reflected back.
Bats used sound reflection for echolocation to determine the position of nearby objects.
Also, they use it to determine the shape and size of objects.
The mechanism where bats use sound to determine location is known as echolocation. The bat picks up the reflected sound and projects the location of their targets.Answer:
B
The sound waves are reflected.
Explanation:
Calculate the solubility of Zn(OH)2 in water at 25°C.
Answer:
The solubility of Zn(OH)₂ at 25ºC is 1.96x 10⁻⁶,
Explanation:
The solubility is the maximum amount of a solute that can be dissolved in a certain volume of liquid (usually water) at a given temperature.
First, we write the dissolution reaction of Zn(OH)₂ in water, which is:
Zn(OH)₂ (s) ⇄ Zn²⁺ + 2 OH⁻
We know that the Kps, that is, the dissolution equilibrium constant for this compound at 25ºC is 3.0x 10⁻¹⁷.
Therefore, the Kps is:
Kps= [Zn²⁺][OH⁻]² (since Zn(OH)₂ is solid, it is not accounted for).
Given the reaction, we can see that for every single Zn²⁺ ion, two OH⁻ ions are produced. Therefore, if the concentration of Zn²⁺ dissolved is x M, the concentration of OH⁻ dissolved will be 2x M.
Substituting these values in Kps, we have:
[Zn²⁺][OH⁻]² = (x)(2x)² = 3.0x 10⁻¹⁷
4x³ = 3.0x 10⁻¹⁷
x= ∛ (3.0x 10⁻¹⁷ ÷ 4)
x= 1.96x 10⁻⁶
Therefore, the molar solubility of Zn(OH)₂ at 25ºC will be 1.96x 10⁻⁶.
A solution is made by mixing of 42.g water and 77.g of acetic acid HCH3CO2. Calculate the mole fraction of water in this solution.
Moles of [tex]H_2O[/tex] ,
[tex]n_{H_2O}=\dfrac{42}{2\times 1 + 16}=\dfrac{42}{18}\\\\n_{H_2O}=2.33\ moles[/tex]
Moles of acetic acid [tex]HCH_3CO_2[/tex] ,
[tex]n_{A.A}=\dfrac{77}{1 + 12 + 3 + 12 + 16\times 2}=\dfrac{77}{60}\\\\n_{A.A}=1.28\ moles[/tex]
Mole fraction of water :
[tex]M.F_{H_2O}=\dfrac{n_{H_2O}}{n_{H_2O}+n_{A.A}}\\\\M.F_{H_2O}=\dfrac{2.33}{2.33+1.28}\\\\M.F_{H_2O}=0.645[/tex]
Therefore, mole fraction of water in this solution is 0.645 .
Hence, this is the required solution.
2. Which gas is NOT an efficient greenhouse gas?
A. Helium
B. Methane
C. Carbon dioxide
D. Water vapor
Answer:
helium
Explanation:
remaining three are efficient gas
Among the options given below, helium is not an efficient greenhouse gas. Thus, the correct option for this question is A.
What do you mean by Greenhouse gases?Greenhouse gases are those gases that significantly allow solar radiation in order to enter but prevent the escape of heat radiations of longer wavelengths. The names of common greenhouse gases are carbon dioxide, methane, nitrous oxide, CFCs, etc.
According to the context of this question, the presence of these gases in the atmosphere is responsible for the phenomenon of keeping the earth warm. This is known as Greenhouse effect. These gases stimulate the phenomenon of global warming.
Therefore, among the options given below, helium is not an efficient greenhouse gas. Thus, the correct option for this question is A.
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What are the building blocks of proteins?
O sugars
O fatty acids
O amino acids
O nitrogen bases
Answer:
amino acids
Hope this helps:)
Answer:
C: Amino Acids on edge
Explanation:
Can you guys help me answer question 5 on homogeneous mixture tysm
Answer:
Hope this helped :) good luck! ❤️
Explanation:
A coolant solution is a homogeneous mixture because the coolant particles are not chemically combined with the water (keep their properties) and they are evenly distributed throughout the water.
• Why does a carpeted floor feel warmer to bare feet than tile or wood even though
all surfaces are the same temperature?
As air undergoes conduction better in tile than in carpet, hence a carpeted floor feel warmer to bare feet than tile or wood even though all surfaces are the same temperature.
What is conduction?
Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.
In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .
When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:
1) heat conduction
2) electrical conduction
3)sound conduction
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Item 10
What color do acids turn litmus paper?
yellow
red
pink
blue
Answer:
red
Explanation:
blue litmus paper turns red under acetic conditions and red lettuce paper turns blue under basic and alkaline conditions with the color change occurring over the PH range the neutral litmus paper is purple
The answer is red.
took the test.
The pressure caused by a sample of gas is 2.25 atm. 1 atm is
equal to 1.01 kPa. What is the pressure in Newton per square
centimeter?
Answer:
[tex]0.326\frac{N}{cm^2}[/tex]
Explanation:
Hello.
In this case, considering that 1 atm equals 1.01 kPa, we can compute the pressure in kPa first as shown below:
[tex]2.25atm*\frac{1.01kPa}{1atm} =3.26kPa[/tex]
Now, we convert kPa to Pa, considering 1 kPa equals 1000 Pa:
[tex]3.26kPa*\frac{1000Pa}{1kPa}=3260Pa[/tex]
Now, since Pa is equal to N/m², and 1 m equals 100 cm, the pressure in newton per square centimeter turns out:
[tex]3260\frac{N}{m^2}*(\frac{1m}{100cm})^2 \\\\0.326\frac{N}{cm^2}[/tex]
Best regards.
What is an extremophile? What domain is known for these organisms?
Extremophiles are bacteria, archaea, as well as eukarya across all three domains of life. Cells make up every organisms.
What is Extremophiles?Extremophiles contain bacteria, archaea, as well as eukarya from all three domains of life.
What is organisms ?Any organic, biological system which works as a separate entity was referred to as an organism.
Extremophiles are organisms that can survive in harsh settings, such as those with high temperatures, radiation, salt, or pH levels. In the planet's evolutionary development, several creatures have been ecologically dominating.
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What is the maximum amount of water (in grams) that can be removed from 15ml of toluene by the addition?
Complete Question
Magnesium sulfate forms a hydrate with the formula [tex]MgSO_4. 7H_20[/tex]. What is the maximum amount of water (in grams) that can be removed from 15 ml of toluene by the addition of 200 mg of anhydrous magnesium sulfate? The molar mass of [tex]MgSO_4[/tex] is 120.4 g/mol; H20 = 18 g/mol.
Answer:
The value is [tex]z = 0.2093 \ g[/tex] of [tex]H_2O[/tex]
Explanation:
From the question we are told that
The volume of toluene is [tex]V = 15 mL[/tex]
The mass of anhydrous magnesium sulfate is [tex]m = 200m g = 200 *10^{-3} \ g[/tex]
The formula of the hydrate is [tex]MgSO_4. 7H_20[/tex]
The molar mass of [tex]MgSO_4[/tex] is [tex]z =120.4 \ g/mol[/tex]
From the formula given we see that
1 mole of [tex]Mg SO_4[/tex] wil remove 7 moles of [tex]H_2O[/tex] to for the given formula
Hence
120.4 g (1 mole) will remove 7 moles (7 * 18 g = 126 g ) of [tex]H_2O[/tex] to for the given formula
Therefore 1 g of [tex]Mg SO_4[/tex] x g of [tex]H_2O[/tex]
So
[tex]x = \frac{x]126 * 1}{ 120.4 }[/tex]
=> [tex]x = 1.0465 \ g [/tex]
From our calculation we obtained that
1 g of [tex]Mg SO_4[/tex] will remove [tex]x = 1.0465 \ g [/tex] of [tex]H_2O[/tex]
Then
[tex]200 *10^{-3} \ g[/tex] of [tex]Mg SO_4[/tex] will remove z g of [tex]x = 1.0465 \ g [/tex] of [tex]H_2O[/tex]
So
[tex]z = 200 *10^{-3} * 1.0465[/tex]
=>[tex]z = 200 *10^{-3} * 1.0465[/tex]
=>[tex]z = 0.2093 \ g[/tex] of [tex]H_2O[/tex]
Does anyone know this?
Answer:
B
Explanation:
The entropy will increase as the ice melts. While in a solid state (ice) entropy is lower because the molecules are ordered and in a set position. As the ice melts the molecular have a larger area to roam. When going from a solid state to a liquid state, entropy rises. When going from a liquid state to a gaseous state, entropy rises.
Mass number is equal to
(10 Points)
O neutrons and electrons
o electrons and protons
O protons and nucleus
protons and neutrons
The system is originally at equilibrium with [butane] = 1.0 M and [isobutane] = 2.5 M.If 0.50 mol/L of isobutane is suddenly added and the system shifts to a new equilibrium position, what is the equilibrium concentration of butane?
Answer:
1.14 M
Explanation:
Let's consider the following reaction.
butane ⇄ isobutane
We can use the concentrations at equilibrium to calculate the equilibrium constant.
Kc = [isobutane] / [butane]
Kc = 2.5 / 1.0
Kc = 2.5
If we add 0.50 M of isobutane, we get [isobutane] = 2.5 + 0.50 = 3.0 M.
This will be an initial concentration in an ICE chart.
butane ⇄ isobutane
I 1.0 3.0
C +x -x
E 1.0+x 3.0-x
The equilibrium constant is:
Kc = 2.5 = [isobutane] / [butane]
2.5 = (3.0-x) / (1.0+x)
2.5 + 2.5x = 3.0-x
x = 0.14
The equilibrium concentration of butane is:
[butane] = 1.0+x = 1.14 M
Describe in your own words the sequence of reactions occurring in your muscle
tissue cells when oxygen is "dropped off from the blood.
Answer:
Even though oxygen is transported via the blood, you may recall that oxygen is not very soluble in liquids. A small amount of oxygen does dissolve in the blood and is transported in the bloodstream, but it is only about 1.5% of the total amount. The majority of oxygen molecules are carried from the lungs to the body’s tissues by a specialized transport system, which relies on the erythrocyte—the red blood cell. Erythrocytes contain a metalloprotein, hemoglobin, which serves to bind oxygen molecules to the erythrocyte (Figure 1). Heme is the portion of hemoglobin that contains iron, and it is heme that binds oxygen. One hemoglobin molecule contains iron-containing Heme molecules, and because of this, each hemoglobin molecule is capable of carrying up to four molecules of oxygen. As oxygen diffuses across the respiratory membrane from the alveolus to the capillary, it also diffuses into the red blood cell and is bound by hemoglobin. The following reversible chemical reaction describes the production of the final product, oxyhemoglobin (Hb–O2), which is formed when oxygen binds to hemoglobin. Oxyhemoglobin is a bright red-colored molecule that contributes to the bright red color of oxygenated blood.
Hb + O2 ↔ Hb − O2
How are ecological islands different from geographical islands as described from the reading in the text?
Answer:
Ecological islands is just a terminology used, since it isn't surrounded by water like an actual island, instead, it's something isolated from other things, which is the same thing as an island in a way:
Island (geographical) - Land isolated from bigger "main" land masses by water.
Island (ecological) - Land which contains certain isolated features (habitat, plants, etc.).
Explanation:
An ecological island is an area of land, isolated by natural or artificial means from its surrounding land while geographical islands are a body of land surrounded by water.
What are ecological islands and geographical islands?An ecological island refers to an area of land which is not necessarily an actual island but isolated by natural or artificial means from the surrounding land. A natural micro-habitat exists on sich lands amidst a larger differing ecosystem.
In artificial ecological islands, all non-native species are eradicated, native species are reintroduced and nurtured, and the natural or artificial border is maintained to prevent the reintroduction of non-native species.
A geographical island is a body of land surrounded by water. Continents are also surrounded by water as they are so big but they are not considered islands. Islands may be categorized as either continental or oceanic.
There are so many islands in the lakes, oceans, and rivers around the world. They vary in climate, size, and the types of organisms that inhabit them.
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At a given temperature, the equilibrium constant for the formation of HI from H2 and I2 was found to be 29.9. Calculate the equilibrium constant for the decomposition of HI.
Answer:
The correct answer is: K'= 0.033.
Explanation:
The formation of HI from H₂ and I₂ is given by:
H₂ + I₂ → 2 HI K= 29.9
The decomposition of HI is the reverse reaction of the formation of HI:
2 HI → H₂ + I₂ K'
Thus, K' is the equilibrium constant for the reverse reaction of formation of HI. It is calculated as the reciprocal of the equilibrium constant of the forward reaction (K):
K' = 1/K = 1/(29.9)= 0.033
Therefore, the equilibrium constant for the decomposition of HI is K'= 0.033
What should be the temperature of the solvent before adding it to the sample to be recrystallized?
Answer:
Near the boiling point of the solvent
Explanation:
The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point. At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of the hot solvent is required to dissolve the solute.
Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.
Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.
The wood in my house is crumbling. *
Problem
Hypothesis
Law
Theory
Answer:
Problem
Explanation:
The given statement is a problem. It states the problem that the house of the speaker has been undergoing with. This problem gives rise to the Hypothesis in which the 'why' question is asked. The reason of the crumbling of the wood is stated in the hypothesis. Any reason placed of the happening of the event is stated to be hypothesis.
1. Which of the following are properties of non-metals?
A. mostly solids, dull, brittle, reactive, conductors
B. mostly solids, luster, high density, conductors
C. mostly gases, brittle, dull, low density, insulators
D. solids, luster, brittle, conductors, medium density
1. The center of the atom is called the
(10 Points)
O nucleus
O protons
electrons
neutrons
Percent error of 76.48
Answer:
Explanation:
i’m not sure but I think it’s 7648%
The molar mass of gallium (Ga) is 69.72 g/mol.
Calculate the number of atoms in a 27.2 mg sample of Ga.
Write your answer in scientific notation using three significant figures.
atoms Ga
Answer:
2.35 x 10²⁰ atoms Ga
Explanation:
After converting from mg to g, use the molar mass as the unit converter to convert to moles. Then using Avogadro's number, 6.022 x 10²³ convert from moles to atoms of Ga.
[tex]27.2mgGa*\frac{1g}{1000mg} *\frac{1 mol Ga}{69.72gGa} *\frac{6.022*10^2^3 atoms Ga}{1 molGa} = 2.349 * 10^2^0 atoms Ga[/tex]
Then round to 3 significant figures = 2.35 x 10²⁰ atoms Ga.
The number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
StoichiometryFrom the question, we are to calculate the number of atoms in a 27.2 mg sample of Ga.
First, we will determine the number of moles of Ga present
Using the formula,
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass} [/tex]
Mass = 27.2 mg = 0.0272 g
Molar mass = 69.72 g/mol
Then,
[tex]Number\ of\ moles \ of\ Ga = \frac{0.0272}{69.72} [/tex]
[tex]Number\ of\ moles \ of\ Ga = [/tex] 0.000390132 moles
Now, for the number of atoms present
From the formula
Number of atoms = Number of moles × Avogadro's constant
Then,
Number of Ga atoms = 0.000390132 × 6.022×10²³
Number of Ga atoms = 2.35 × 10²⁰ atoms
Hence, the number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
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What is the melting point of the substance?
2) (3 pts) Convert 85 oF to oC.
Answer:
The answer will be 29.4˚C.
Explanation:
Using the formula 5(˚F-32)/9, plug in the numbers and you'll get 29.4˚C.