An atom of which element has the largest atomic radius?
A)
B
B)
Be
C)
N
D)
Ne
Answers
Answer:
B) Be
Explanation:
Across the period (going from left to right of the periodic table), the atomic radius decreases. Beryllium is located further on the left of the periodic table compared to the other elements in the option and thus it has the largest atomic radius.
Explanation of trend:
Across the period, the number of protons and electrons increases in the atom. Electrons are added to the valence shell, hence the electrons added are not able to shield the increased nuclear charge well. (Since shielding effect is most effective when core electrons shield the valence electrons) Therefore, the effective nuclear charge (ENC) increases. As ENC increases, valence electrons are increasingly attracted to the nucleus. They are drawn closer to the nucleus, and so the atomic radius decreases across the period.
What is ENC?
ENC is the net nuclear charge acting on the valence electron (since the valence electron experiences electrostatic forces of attraction by the positively charged protons in the nucleus, and an electron-electron repulsion force by the core electrons)
➣ ENC
= nuclear charge (atomic no.) - shielding constant (no. of core electrons)
See diagram: black arrow represents the shielding effect (also known as electron-electron repulsion), while the orange arrows represent the nuclear charge (electrostatic forces of attraction)
Related Questions
At 25ºC, the average velocity of a hydrogen molecule is 1.92 x 103 m/s. What is the average velocity of a nitrogen molecule at the same temperature?
NEED WORK
Answers
Answer:
V = 513.36m/s
Explanation:
Temperature (T) = 25°C = (25 + 273.15) = 298.15K
Speed (V) = 1.92*10³m/s
According to kinetic theory of gases, the speed (v) of a molecule is
V= √(3RT / M)
V = speed or velocity
R = ideal gas constant = 0.082J/mol.K
T = temperature of the gas
M = molar mass
Molar mass of hydrogen molecule = 2.0g/mol
Molar mass of Nitrogen molecule = (2×14.0) = 28.0g/mol
Since they're in the same temperature
V1 / V2 = √(M2 / M1)
1.92×10³ / V2 = √(28 / 2)
1.92×10³ / V2 = √(14)
1.92*10³ / V2 = 3.74
1.92*10³ = 3.74V2
V2 = 1920 / 3.74
V2 = 513.36m/s
The velocity of Nitrogen molecule is 513.36m/s
Why is a chemical equilibrium described as dynamic?
Answers
Answer:
Chemical equilibrium is also called as dynamic equilibrium because it in chemical equilibrium, the equilibrium can shift towards both sides that is reactant and product known as equilibrium shifting. And in chemical equilibrium, the reaction is going on but the rate of formation of reaction is equals to the rate of formation of product.
Hope this helps!
what happens to the density of a box full of leaves if you crush up all the leaves and place them in another box
A the density increases
B the density stays the same
C the density decreases
D the density first decreases, then increases
Answers
Answer:
B the density stays the same
A typical cell phone uses wavelength of 0.36meters. How much energy does this wave have?
Answers
Answer:
55×10^-26 J
Explanation:
We can calculate the energy of the wave from
E= hc/λ
Where
h= Planks constant = 6.6×10^-34 Is
c= speed of light = 3×10^8 ms-1
λ= wavelength of the wave = 0.36 metres
Recall that cell phone use radio waves which belong to the electromagnetic spectrum hence it must possess the speed of light.
E= 6.6×10^-34 × 3×10^8/ 0.36
E= 55×10^-26 J
Hence the energy possessed by 0.36 meters wavelength radio waves is 55×10^-26 J
how many moles of solute are present in 50.0 ml of 0.20 m kno3
Answers
Answer: Volume = 50.0 mL in liters : 50.0 / 1000 = 0.05 L
n = M x V
n = 0.20 x 0.05
n = 0.01 moles of solute
Explanation:
The number of moles of solute are present in 50.0 mL of 0.20 M of KNO₃ solution is 0.01 moles.
How do we calculate moles?Moles will be calculated by using the molarity formula because molarity is define as the no. of moles of solute present in per liter of the solution as:
M = n/V, where
M = molarity of KNO₃ = 0.2 M
V = volume of solution = 50mL = 0.05L
Moles will be calculated as:
n = (0.2)(0.05) = 0.01 moles
Hence required moles are 0.01 moles.
To know more about molarity, visit the below link:
https://brainly.com/question/26528084
Need help with these three pls!!!!!
Answers
False
True
Will someone actually help me and not just something random
Answers
Answer:
D
Explanation:
CORO
Name three ways that scientists can ensure their results
are reliable
Answers
Answer:
Reliability. When a scientist repeats an experiment with a different group of people or a different batch of the same chemicals and gets very similar results then those results are said to be reliable. Reliability is measured by a percentage – if you get exactly the same results every time then they are 100% reliable.
Explanation:
Sorry, I only got one way.
identify as the following as an element or a compound. its not multiple choice a) NaCI b) AR d) 02 c) CH4 d) 02 e) CI
Answers
Answer:
A. compound (NaCl)
B. element (note: it should be Ar. AR is not an element or compound.)
c. compound (CH4)
d. element (O2)
e. element (Cl)
Explanation:
Element is single and by its self. A compound is multiple elements put together.
_____________ is the energy stored because of its position or shape.
A. Potential energy
B. Kinetic energy
C. Thermal energy
D. Chemical energy
Answers
Answer:
Potential Energy is the energy stored because of its position or shape
Explanation:
Which of these would be an appropriate way to describe the concentration of orange candies? Check all that apply
the number of orange candies divided by total number of candies
the mass of orange candies divided by total mass of candies
the volume of brown candies divided by volume of orange candies
the actual number of orange candies
the number of orange candies divided by number of brown candies
the number of orange candies plus number of brown candies
Answers
Answer:
the number of orange candies divided by total number of candies
the mass of orange candies divided by total mass of candies
Explanation:
The two correct options that are appropriate to describe the concentration of orange candies would be the number of orange candies divided by total number of candies and the mass of orange candies divided by total mass of candies.
The concentration of a substance can be described as the fraction of that substance in a particular mix of substances.
In term of number, the concentration of a substance in a mix of substances can be expressed as the number of that substance divided by the total number of substances in the mix.
In term of mass, the concentration of a substance in a mix of substances can be expressed as the mass of that substance divided by the total mass of the mix.
Answer:
A, B, E
Explanation:
edge
Which substance should a student apply to the skin if he or she gets splashed with an acid?
Answers
What is the pH of a 0.083 solution of HCI
Answers
Answer:
The pH is 1.08, being an acid pH
Explanation:
pH is a parameter used to measure the degree of acidity or alkalinity of a substance. The pH scale ranges from 0 to 14. Values less than 7 indicate the acidity range and those greater than 7 indicate alkalinity or basicity. Value 7 is considered neutral. Mathematically, pH is the negative logarithm of the molar concentration of hydrogen or proton ions (H⁺) or hydronium ions (H₃O⁺).
pH= - log [H⁺]= - log [H₃O⁺]
A strong acid is an acid that completely dissociates into hydrogen ions and anions in solution. This implies that the initial concentration of acid is equal to the final concentration of H₃O⁺. This occurs with acid HCl.
So, pH is calculated as:
pH= - log (0.083)
pH= 1.08
The pH is 1.08, being an acid pH
How do the particles of a gas differ from the particles of a solid?
Answers
Answer:
Gas is more open particles
Explanation: gas can flow
Choose the correct word to make an
appropriate hypothesis for this example.
If
is added to water, then the
boiling point of water increases because
solutions have
boiling points than pure liquids if
pressure remains unchanged.
Answers
Answer: salt , higher.
Explanation:
Doing it right now
Answer:
salt, higher
Explanation:
edge
1. Which gas will move faster through a small opening hydrogen or oxygen? *
A)hydrogen
B) oxygen
Answers
Answer:
hydrogen
Explanation:
What kind of energy transformations occur when you hit a coconut with a hammer
Answers
sound energy, kinetic energy,
i cant think of any more but hope this helps
Answer:
Mechanical to kinetic to sound to heat
Explanation:
Remember that all types of energy transformation end in heat
how does atomic spectrum differ from continuous spectrum
Answers
Answer:
A continuous spectrum is a record formed by collecting light of all frequencies traveling through space together. ... A line spectrum is a record formed by collecting light emitted from excited atoms whose electrons are falling back down to lower energy states.
Explanation:
What is one thing NOT impacted by Acid
Rain.
A)Granite
B)Metal
C)Limestone
Answers
Fossil fuels, like coal, oil, and natural gas, are huge, carbon-rich deposits that essentially trapped carbon for millions of years (until humans started burning them for energy).
True or False
Answers
Answer:
True!
Explanation:
Fossil fuels are carbon based compounds present deep in the earth left millions of years ago.
hope it helps!
If the percent (mass/mass) for a solute is 16% and the mass of the solution is 400 g,
What is the mass of solute in solution
Answers
Answer:
[tex]m = 64\,g[/tex]
Explanation:
The mass of the solute is given by the following expression:
[tex]m = 0.16\cdot (400\,g)[/tex]
[tex]m = 64\,g[/tex]
how many Atoms of chlorine Cl are there in 3.45 mol Cl?
Answers
Answer:
2.078x10^24
Explanation:
No. of atoms of chlorine = 3.45 x 6.022x 10 ^23 x 1
= 2.078x10^24
( to find no. of atoms of, heres the formula i was taught No. of atoms = no. of moles x Avogadros constant x no. of atoms in the formula of compound)
Use the drop-down menus to identify each substance as an organic or inorganic compound
ozone (O3):
methane (CH4):
aluminum hydroxide (Al(OH)3):
butane (C4H10):
carbon monoxide (CO):
Answers
Answer:
ozone (O3): inorganic
methane (CH4): organic
aluminum hydroxide (Al(OH)3): inorganic
butane (C4H10): organic
carbon monoxide (CO): inorganic
Explanation:
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. Some simple compounds that contain carbon are often considered inorganic. Examples of inorganic compounds include carbon monoxide , carbon dioxide , carbonates, carbides , cyanides, cyanates, and thiocyanates. Most of these compounds are normal parts of mostly organic systems, including living organisms. When a chemical substance is classified as inorganic, it does not necessarily mean that it does not occur within
living things.
Organic compounds typically contain the carbon-hydrogen bonds. The carbon atoms often catenate and most organic substances occur in living systems and are products of biochemical reactions in living organisms. However, organic substances can also be synthetic and can be prepared in the laboratory.
Answer:
inorganic
organic
inorganic
organic
inorganic
Explanation: trust me
What does “moving slow” mean to a geologist?
Answers
A landslide can be defined as a mass movement of material (e.g., rocks), which moves down a steep slope. A geologist is an expert that studies SLOW-MOVING landslides on a geological scale.
Landslides can occur suddenly or more slowly over long periods of time.
On a geological scale, landslides occur slowly so they are imperceptible to humans.
A geologist is a professional who investigates landslides on a geological scale, which is coarse on a human time-frame.
In conclusion, a geologist is a professional who investigates SLOW-MOVING landslides on a geological scale.
Learn more in:
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How many moles of calcium chloride are contained in a 333 gram sample?
*
A) 8.82 moles
B) 0.333 moles
C) 4.30 moles
D) 0 3.00 moles
Answers
Answer & Explanation:
The molar mass of calcium chloride is 110.98 g/mol. We can use this information to solve this problem. We can set up our equation like this..
[tex]\frac{333 g(CaCl2)}{} *\frac{1mol(CaCl2)}{110.98g(CaCl2)}[/tex]
Multiply straight across on the top and straight across on the bottom.
[tex]\frac{333}{110.98}[/tex]
Now divide.
[tex]\frac{333}{110.98}=3.00[/tex]
So, there are 3.00 moles of calcium chloride contained in a 33 gram sample which is answer choice D.
which spheres are part of the earth system
Answers
Answer:
Everything in Earth's system can be placed into one of four major subsystems: land, water, living things, or air. These four subsystems are called "spheres." Specifically, they are the "lithosphere" (land), "hydrosphere" (water), "biosphere" (living things), and "atmosphere" (air).
Explanation:
List three facts or accomplishments of Modern India (India today)
Answers
Answer:
India is one of the oldest countries in the world and is found in the Asian continent of the world.
They are known as the most populous country in the world.
They also have a greater linguistic diversity than any other large country. Lots of languages are available and accepted in the country.
They are very vast in Agriculture and accounts for 40percent of Mango production in the world
Explanation:
India is the largest producer. India is also the world's largest tea and spices producer. The country manufactures many pharmaceuticals, textiles, and electric goods that are used worldwide. More people in India have access to phones than to sewage systems.
How much of this reactant should he order to make
sure he runs out of both reactants at the same
time? Round to the nearest hundredth and do not
round any of your work until the very end.
g of the limiting
He should uder
reactant.
Answers
Answer:
the answer is Fe2O3
Explanation:
The thermite reaction is described by the equation below: A welder has ... How much of this reactant should he order to make sure he runs out of both reactants at the same time? Round to the nearest hundredth and do not round any of your work until the very end. He should order Fe2O3 g of the limiting reactant.
Answer:
92.41g
Explanation:
Which of these Electromagnetic waves has the most kinetic energy and can be
dangerous?
O radio waves
O gamma rays
O ultraviolet waves
O visible light
Answers
Answer:
Gamma Rays.
Explanation:
Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength.
B. If the sand you ran across has a specific-heat capacity of 835 J/(kgºc),
how much energy must be added to a 2-kilogram pile of it to increase its
temperature from 40°C to 50°C? Show your work. (3 points)
Answers
Answer: 16700 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
[tex]Q=m\times c\times \Delta T[/tex]
Q = Heat absorbed = ?
m = mass of sand = 2 kg
c = heat capacity = [tex]835J/kg^0C[/tex]
Initial temperature = [tex]T_i[/tex] = [tex]40^0C[/tex]
Final temperature= [tex]T_f[/tex] = [tex]50^0C[/tex]
Change in temperature ,[tex]\Delta T=T_f-T_i=(50-40)^0C=10^0C[/tex]
Putting in the values, we get:
[tex]Q=2kg\times 835J/kg^0C\times 10^0C[/tex]
[tex]Q=16700J[/tex]
16700 J of energy must be added to a 2-kilogram pile of it to increase its temperature from 40°C to 50°C
