Answer:
4. O^2-
Explanation:
O^2 has 16 electrons, while Ne has 18 electron. O^2- is a molecule that has one electrons added to each atom, meaning that there are two extra electrons. Which makes O^2 the same electron configuration as an atom of neon.
The ions having same electronic configuration as neon are Calcium, oxygen, and chlorine ion. Thus, options 1, 2, and 4 are correct.
The electronic configuration has been defined as the electron address in a atom. The electronic configuration has been based on the quantum rule for the filling of the electrons.
The number of electrons present in Neon has been 18. Thus, the ion with the presence of 18 electrons has same electronic configuration as Neon.
The number of electrons in the following ions are:
[tex]\rm Ca^{2+}=18\\Cl^-=18\\Li^+=4\\O_2^{-}=18[/tex]
The number of electrons of calcium ion and chlorine ion are similar to the number of electrons of Ne. Thus the ions having same electronic configuration as neon are Calcium, oxygen and chlorine ion. Thus, options 1, 2, and 4 are correct.
For more information about electronic configuration, refer to the link:
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Which type of energy is always generated, at least in small amounts, when an energy transfer or transformation accounts? A. Potential energy
B.thermal energy
C. Chemical energy
D. Radiant energy
Approximately how many joules of heat are required to raise the temperature of 20 grams of water from 30°C to 40°C?
A
134 J
B
168 )
C.
420 j
D.
840 J
The heat required : 840 J
Further explanationGiven
mass of water = 20 g
Temperature : 30°C to 40°C
Required
Heat to raise the temperature
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C (for water= 4.18 J/g° C)
∆T = temperature difference, ° C / K
The heat :
[tex]\tt Q=20\times 4.2\times (40-30)\\\\Q=\boxed{\bold{840~J}}[/tex]
A 90.00 g sample of Na, CO *xH, O is heated until all of the water is driven
off, forming 32.28 g of the anhydrous salt, Na, Coz. What is the percent by
mass of H,O in the hydrated compound, Na CO, *xH,O?*
The percent by mass of H₂O in the hydrated compound, Na₂CO₃.xH₂O = 64.13%
Further explanationGiven
90 g sample Na₂CO₃.xH₂O
32.28 g Na₂CO₃
Required
The percent by mass of H₂O
Solution
mass of H₂O = mass of sample - mass of the anhydrous salt, Na₂CO₃
[tex]\tt mass~H_2O=90-32.28=57.72~g[/tex]
The percent by mass :
[tex]\tt \%mass~H_2O=\dfrac{mass~H_2O}{mass~sample}\times 100\%\\\\\%mass~H_2O=\dfrac{57.72}{90}\times 100\%\\\\\%mass~H_2O=64.13\%[/tex]
The element copper with a relative atomic mass of 63.55 contains atoms of mass numbers 63 and 65. Calculate the fraction of each isotope.
Explanation:
Difference between 63 and 65 = 2.
(63.55 - 63) / 2 * 100% = 27.5%.
(65 - 63.55) / 2 * 100% = 72.5%.
Hence there is 72.5% of the isotope with atomic mass 63 and 27.5% of the isotope with atomic mass 65 in copper.
Which of the following would be found ONLY in plant cells
Answer:
chloroplasts, cell walls, or intracellular vacuoles
Explanation:
You didn't list the following, but I'm guessing it is chloroplasts, cell walls, or intracellular vacuoles
CO2 + H2O → H2CO3. If 495 milliliters of carbon dioxide at 25°C and 101.3 kilopascals reacts with excess water, what is the theoretical yield of carbonic acid?
Answer:
The theoretical yield of carbonic acid is 1.24 grams.
Explanation:
The balanced equation for the formation of carbonic acid by the reaction of carbon dioxide with water is:
CO₂ + H₂O → H₂CO₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reactant and product participate:
CO₂: 1 moleH₂O: 1 moleH₂CO₃: 1 moleAn ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
Moles of carbon dioxide can be calculated using ideal gas law equation. In this case:
P= 101.3 kPa= 1 atmV= 495 mL= 0.495 L (being 1,000 mL=1 L)n=?R= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 25 C= 298 K (being 0 C=273 K)Replacing:
1 atm* 0.495 L= n* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] *298 K
Solving:
[tex]n=\frac{1 atm*0.495 L}{0.082\frac{atm*L}{mol*K}*298 K }[/tex]
n= 0.02 moles
Then, by reaction stoichiometry 0.02 moles of carbon dioxide produces 0.02 moles of carbonic acid.
Since the molar mass of carbonic acid is 62.03 g/mol, then you can apply the following rule of three: if there are 62.03 grams in 1 mole, how much mass is there in 0.02 moles?
[tex]mass=\frac{0.02 moles*62.03 grams}{1 mole}[/tex]
mass= 1.24 grams
The theoretical yield of carbonic acid is 1.24 grams.
What is a net ionic equation?
A. An equation that is balan
B. An equation that shows a
Answer:
Explanation:
An equation showing only what is involved in the reaction.
a o e x
A nuclear reaction in which the nuclei of atoms join together is called nuclear fission.
true or false
Answer:
That is true!
Explanation:
During photosynthesis, plants take carbon dioxide from the air and water and convert them into:
A. amino acids
B. glucose and oxygen
C. oxygen and chlorophyll
D. water and sunlight
Answer:
c I am pretty sure it's c because I learned this today in science and I think that what it is but if it's not see then it's I don't know
Dust storms in the Sahara desert carry mineral nutrients across the Atlantic Ocean to replenish the supply leached out of the soils of the Amazon basin. What was an important mineral fertilizer delivered this way, mentioned in the video?
Answer:
Phosphorus.
Explanation:
Phosphorus is the important fertilizer which comes through the dust storms of Sahara desert and provides this nutrient to the soils of the Amazon basin. Phosphorus is an important macronutrient that is necessary for the growth and development of plants so we can conclude that this dust storms are very important for the fertility of the soils present in Amazon basin.
Can gravity be considered a force?
Answer: Gravity is considered a universal force because it acts between any two masses anywhere in the universe.
Answer:
Gravity (from Latin gravitas 'weight'[1]), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light[2]—are brought toward (or gravitate toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides.
wo people push on the same door from opposite sides as shown.
A man pushes on a door from the left. A woman pushes on the door from the right.
They will only see the door move when
both people exert the same force so that the forces are unbalanced.
neither person exerts a force on the door so that the net force is zero.
one person exerts more force than the other so that the forces are unbalanced.
both people exert the same force so that the forces are balanced.
Answer is:
When one person exerts more force than the other so that the forces are unbalanced........ maybe, im not sure if im right
Answer:
c
Explanation:
How many moles are in 34.2 g Ca
Answer:
0.855 moles are present in 34.2 g of Ca
point Deshawn ran the 400 m race(in a straight line) in 2 minutes. What is his distance and displacement ? Explain your answer below in complete sentences.
His distance and displacement are the same, which was 400 m
Further explanationGiven
Distance = 400 m
time = 2 min
Required
Distance and displacement
Solution
Distance is a scalar quantity that indicates the length of the trajectory that is traveled by an object within a certain interval. Distance has no direction, only has magnitude
Can be simplified distance = totals traveled
Displacement is a vector quantity that shows changes in the position of objects in a certain interval of time. Displacement has magnitude and direction
Can be simplified displacement = distanced traveled from starting point to ending point
From the definition above shows that the displacement and the distance that he traveled have the same value (magnitude), which is equal to 400 m
The value of the two will be different if he starts and finishes at the same point, then the displacement value is zero while the distance he has traveled is still 0
determine the frequency and wavelength (in nm) of the light emitted when the e- fell from n=4 and n=2
Answer:
Frequency = 6.16 ×10¹⁴ Hz
λ = 4.87×10² nm
Explanation:
In case of hydrogen atom energy associated with nth state is,
En = -13.6/n²
For n = 2
E₂ = -13.6 / 2²
E₂ = -13.6/4
E₂ = -3.4 ev
Kinetic energy of electron = -E₂ = 3.4 ev
For n = 4
E₄ = -13.6 / 4²
E₄ = -13.6/16
E₄ = -0.85 ev
Kinetic energy of electron = -E₄ = 0.85 ev
Wavelength of radiation emitted:
E = hc/λ = E₄ - E₂
hc/λ = E₄ - E₂
by putting values,
6.63×10⁻³⁴Js × 3×10⁸m/s / λ = -0.85ev - (-3.4ev )
6.63×10⁻³⁴ Js× 3×10⁸m/s / λ = 2.55 ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 4.08×10⁻¹⁹ J
λ = 4.87×10⁻⁷ m
m to nm:
4.87×10⁻⁷ m ×10⁹nm/1 m
4.87×10² nm
Frequency:
Frequency = speed of electron / wavelength
by putting values,
Frequency = 3×10⁸m/s /4.87×10⁻⁷ m
Frequency = 6.16 ×10¹⁴ s⁻¹
s⁻¹ = Hz
Frequency = 6.16 ×10¹⁴ Hz
1. Which type of blood cell is the most numerous in the body?
O a. red blood cells
O b. white blood cells
c. platelets
d. plasma
Answer:
red blood cells
Explanation:
I'm not so sure though
Clay and Pumice have pores but the pores are not well connected. If you poured water over either of them it would just run off the surface. It wouldn't run through. But they could hold water in their pores. We can say then that both or them ARE ___________________ but NOT __________________________________.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
A porous substance is one which have pores in in through which air or liquid can pass through. Both clay and pumice are porous due to the presence of pores in them. These pores allow air to pass through them. However, since the pores are not well connected water do no pass through them. As a result, clay vessels can hold water within them and pumice floats on water.
Permeability is the ability of a substance to allow other substances to pass through. Both clay and pumice have low permeability, as a result they do not allow water to pass through them. Rather, water runs over their surface when poured over them.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
Please answer on paper and send a picture of the answer. thank you
Answer:
I dont know how to take a picture so I will just tell you the answer. The answer is no.
Explanation:
Hope this helps. :) :D
2. what is the molarity of a 300ml solution which is 25%by mass H2S04?
the solutions mass is 353.4g
Answer:
3 M
Explanation:
Molarity is calculated by dividing the moles of the solute by the liters of solution. In this problem, we are given that the mass of the solution is 353.4 g and that the mass of the solute (H2SO4) is 25% of this.
Thus, you get that the mass of the solute is 88.35 g.
Next, you must convert the mass of the solute into moles. You must use the periodic table to find the molar mass of the solute in order to do the conversion.
Thus, you get that the number of moles of solute is 0.90.
Molarity is then = 0.90 mol/.300 L = 3 M.
The molarity of a 300ml solution of mass 353.4 g which is 25%by mass H₂SO₄ is 2.94 molar.It is calculated from the number of moles of sulphuric acid.
What is molarity?Molarity is a term used to represent the concentration of a solution. Mathematically it is the ratio of the number of moles of solute to the volume of solution in liter.
The mass percent of substance is the ratio of mass of that substance to the total mass. Here, the total mass of the solution is 353.4 g and the solute acid is 25% by mass. Thus mass of the solute is :
353.4 × 25 /100 = 88.3 g.
The molar mass of sulphuric acid is 100 g/mol. Thus number of moles of solute is 88.3 g/100 g/mol = 0.88 moles.
The volume of the solution is 300 ml or 0.3 liter. Now, the molarity of the solution can be calculated as follows:
Molarity = no.of moles of solute/volume in L
= 0.88 mol / 0.3 L
= 2.94 mol/L.
Hence, the molarity of the solution is 2.94 molar.
To find more about molarity, refer the link below:
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A student builds an electromagnet using a battery and coiling wire around a nail. The student observes that the electromagnet attracts pins.
Answer:
A
Explanation:
A
Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm8 at 27 ∘C. (R = 0.083 bar dm8 K−1 mol−1
Answer:
Total pressure = 56.77 bar
Explanation:
Given data:
Mass of dioxygen = 8 g
Mass of dihydrogen = 4 g
Volume of vessel = 1 dm³
Temperature = 27°C (27+273 = 300 K)
R = 0.083 bar.dm³ / mol.K
Total pressure = ?
Solution:
Number of moles of dioxygen:
Number of moles = mass/molar mass
Number of moles = 8 g/ 32 g/mol
Number of moles = 0.25 mol
Pressure of dioxygen:
PV = nRT
P = nRT/V
P = 0.25 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³
P = 6.97 bar.dm³ /1 dm³
P = 6.97 bar
Number of moles of dihydrogen:
Number of moles = mass/molar mass
Number of moles = 4 g/ 2 g/mol
Number of moles = 2 mol
Pressure of dihydrogen:
PV = nRT
P = nRT/V
P = 2 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³
P = 49.8 bar.dm³ /1 dm³
P = 49.8 bar
Total pressure of mixture in a vessel:
Total pressure = P (O₂) + P(H₂)
Total pressure = 6.97 bar + 49.8 bar
Total pressure = 56.77 bar
HELP!!!
find the balanced equation
Answer:
3Fe²⁺ + Cl₂ ⇒ 2Fe³⁺ + 2Cl⁻
Explanation:
manipulate the problem to match charges and have the same amount of reactants and products on both sides.
The standard cell potential for : 3A(s) + B+3(aq) → 3A+(aq) + B(s) is E° = 2.00 V. How does Ecell compare to Eo when [A+] = 0.50, [B3+] = 1.5 x 10-3 at 298 K.
E cell = 1.962 V
Further explanationGiven
E° cell = 2.00 V
Required
E cell at 298 K
Solution
The potential cell for nonstandard conditions we can use the Nernst equation
[tex]\rm E = E ^ o -\dfrac {RT} {nF} lnQ[/tex]
For temperature T = 298 K,
[tex]\rm E = E ^ o -\dfrac {0.0592V} {n} log \: Q[/tex]
Reaction
3A(s) + B+3(aq) → 3A+(aq) + B(s)
Half Reaction
3A(s)⇒3A⁺(aq)+3e⁻
B⁺³(aq)+3e⁻⇒B(s)
n = 3 (3 electron transfer)
Q = the reaction quotient :
[tex]\tt Q=\dfrac{[A^+]^3}{[B^{+3}]}=\dfrac{0.5^3}{1.5.10^{-3}}=83.3[/tex]
E cell :
[tex]\tt E_{cell}=2-\dfrac{0.0592}{3}log~83.3\\\\E_{cell}=1.962~V[/tex]
What is a common form for synthesis reactions?
a. AB → C
b. A + B → BC
c. C → A + B
d. A + B → C
Answer:
The Best Answer would be B but the correct answer is A+B --> AB
Explanation:
What is the BEST reason that the older children did not show the symptoms of pellagra?
I need help!!
Injuries from work related falls can affect employees by resulting in time off and medical cost
Answer:
true
Explanation:
its A
The above statement is considered to be correct and true.
The Occupational Safety and Health Administration (OSHA) is a federal agency that is saddled with the responsibility of assuring and ensuring a safe and healthy working conditions for an employee or group of employees by doing the following;
Setting and enforcing safety standards.Setting and enforcing rules.Providing education.Conducting trainings and assistance to various organizations.According to the Occupational Safety and Health Administration (OSHA), trainings on the adoption and application of safety precautions (tools) such as wearing a personal protective equipment (PPE); face masks (respirators), ear plugs, safety boots, gloves, helmet, etc., are very important and are essentially to be used by all employees (workers) while working in hazard prone environments or industries.
However, when an employee fails to strictly adhere to the recommended OSHA safety precautions, he or she is more likely to sustain a work-related accident or injury from a fall. Thus, this would negatively affect (impact) the employee because it results in him or her being absent from work (time off) and requires some costs to pay for medicals (medical cost).
In conclusion, injuries from work related falls can affect employees by resulting in time off and medical cost.
Find more information: https://brainly.com/question/15442363
What is the base name for the following compound?
C-C-C=0
what are three ways the plates can move
How many valence electrons does Florine have?
O 5
O 7
3
9
Answer:
When forming ions, elements typically gain or lose the minimum number of electrons necessary to achieve a full octet. For example, fluorine has seven valence electrons, so it is most likely to gain one electron to form an ion with a 1- charge
Explanation:
Answer:
7
Explanation:
a-P-e-X
hhhhhhhhhhheeeeeeelppppppp
will give brainliest
Answer:
Kinetic energy.
Explanation: