Answer:
See explanation
Explanation:
Before the advent of the wave-particle duality theory proposed by Louis de Broglie, there was a sharp distinction between mater and waves.
However, Louis de Broglie introduced the idea that mater could display wave-like properties. Erwin Schrödinger developed this idea into what is now known as the wave mechanical model of the atom.
In this model, electrons are regarded as waves. We can only determine the probability of finding the electron within certain high probability regions within the atom called orbitals.
This idea has been the longest surviving atomic model and has greatly increased our understanding of atoms.
How many moles are there in 2.4 x 10 24 atoms of He?
Group of answer choices
6.0 mol
2.4 x 10^24 mol
2.0 mol
4.0 mol
Answer:
4 mol
Explanation:
Given data:
Number of atoms of He = 2.4 × 10²⁴ atoms
Number of moles of He = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.4 × 10²⁴ atoms × 1mol / 6.022 × 10²³ atoms
0.398× 10¹ mol
3.98 mol ≅ 4 mol
To be effective, a certain drug must not drop below 15 mg in the body. A 120
mgs of that drug was administered to a patient. How much time will it take for that drug to reach the 15 mg minimum level. The drug's half-life is 30 minutes.(show how you arrived at your response)
Answer:
90 Minutes
Explanation:
Original concentration = 120 mg
Half life = 30 minutes
Minimum level = 15 mg
Basically, we are to calculate the time it would take to drop from 120 mg to 15 mg.
The half life of a substance is the time it takes for the original concentration of a substance to drop to half it's starting concentration.
First Half life:
Starting concentration = 120mg
Concentration after half life = 120 / 2 = 60 mg
Second Half life;
Starting concentration = 60 mg
Concentration after half life = 60 / 2 = 30 mg
Third Half life;
Starting concentration = 30 mg
Concentration after half life = 30 / 2 = 15 mg
We have reached the minimum 15 mg level. This means it took three half lives to get there.
Total time taken = No of Half lives * Half life duration = 3 * 30 mins = 90 Minutes
Part C
How did Dr. Tierno find the answer to his question?
Answer:
Dr. Tierno tested the pillows for signs of microorganisms. He took samples from the pillow, then he grew the microorganisms in a petri dish.
Explanation:
This is the answer on edmentum
In general, what happens to atoms when they are exposed to extreme temperatures?
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. ... Solids, liquids and gases all expand when heat is added.\
so hope that helps and sooooo
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. ... Solids, liquids and gases all expand when heat is added.
Beryllium is classified as?
a) a transition metal
b) an alkaline earth metal
c) an alkali metal
d) a noble gas
Answer:
b
Explanation:
Beryllium is under Group 2, and group 2 are usually known as alkaline earth metals.
Why do strong storms such as hurricanes usually result in large ocean waves?
A) Hurricanes produce a lot of rain that ends up in oceans
B) A lot of small earthquakes happen during hurricanes
C) Strong winds are produced during hurricanes
D) Hurricanes stir up the ocean floor
Answer:
C
Explanation:
so the way that waves are created normally is by slight breezes the stronger the breeze the bigger the wave so if strong winds are produced it will result in large waves
Hope this helped you and check out my YT my most popular video at Ryetube ExTrEmE
Which of the following explains the VSEPR geometry of a carbon tetrachloride molecule? (5 points)
It is bent because there are four bonded pairs around carbon.
It is tetrahedral because there are four bonded pairs around carbon.
It is bent because there are two bonded pairs and two lone pairs around carbon.
It is tetrahedral because there are two bonded pairs and two lone pairs around carbon.
Answer:
(B) It is tetrahedral because there are four bonded pairs around carbon
Explanation:
CCl4 means four chloride ions bonded covalently with single carbon.
its coordination figure is:
CF = 1/2(Vallence of central atom + electrons donated from substituents - charge)
CF = 1/2(4 + 4.1 - 0)
CF = 4
Bond electrons = 4
Lone pair electrons = 0
Hence, CCl4 is tetrahedral
Mark and Amanda conduct the same investigation as Nguyen, but they use four rocks. They test the same three rocks as Nguyen but add one more rock that has the same color and density as limestone. However, the rock doesn't produce bubbles when acid is added to it. Explain how the mineral composition of this rock compares with that of limestone?
Answer:
The Rock does not contain carbonate in it.
Explanation:
Limestone(CaCO_3) when reacts with a acid produces carbon dioxide, which comes out as bubbles in the solution. It means the 4th rock does not have carbonate in it. Carbonate minerals are unstable in contact with hydrochloric acid. When acid begins to effervesce (fizz) on a specimen. These bubbles confirms the presence of carbonate in mineral.
Answer:
no,exept y and z are similar
Explanation:
litterly what it says '-'
17 OT-
2021
Subject Chemistry Date
7 Evaluate and discuss how do you think
the Number of the Valence electrons
relates to con elements Chemical properties
show many Valence election are found
in the following Atoms.
what is the concentration of a solution which is 2g in 150cm3 in g/dm3
Answer:
13.33 g/dm³
Explanation:
Concentration (g/dm³)= mass(g) ÷ volume (dm³)
Now you need to convert 150 cm³ to dm³
1000cm³ = 1 dm³
thus, 150 cm3= 150 ÷ 1000
= 15dm³
and you already have mass in grams
so concentration = 2 ÷ 0.15
= 13.33 g/dm³ and there you go.. solved ;)
How many moles are 21.67 L of NH4CI?
Type your answer...
Answer:
0.967mole
Explanation:
Given parameters:
Volume of NH₄Cl = 21.67L
Unknown:
Number of moles = ?
Solution:
We assume that the volume was taken at standard temperature and pressure,
Then;
Number of moles = [tex]\frac{volume }{22.4L}[/tex]
Number of moles = [tex]\frac{21.67}{22.4}[/tex] = 0.967mole
An element's atoms are exactly the same - no matter where that element is found.
A.True
B.False
Answer:
B. False
Explanation:
All the atoms of an element are not entirely the same no matter where they are found.
The phenomenon of isotopy brings a different perspective to the identity of an element.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei. Isotopes of an element have the same electrons but differ in their masses. They also differ in their chemical properties.idoine would have chemical properties most like ?
How do fossil fuels play a role in the carbon cycle?(1 point) Fossil fuels require a lot of carbon to burn, which takes carbon out of the atmosphere. Fossil fuels require a lot of carbon to burn, which releases carbon into the atmosphere. Fossil fuels are rich in carbon, and burning them releases carbon into the atmosphere. Fossil fuels are rich in carbon, and burning them returns carbon to the soil.
Answer: Fossil fuels are rich in carbon, and burning them releases carbon into the atmosphere.
Explanation:
The amount of carbon in the form of carbon dioxide in the atmosphere is about 0.03% by volume. This value is kept fairly constant by a natural process known as the CARBON CYCLE. This involves carbon dioxide being continually removed from the atmosphere by plants in photosynthesis, rain water as weak acids while in order to maintain this balance, carbon dioxide is at the same time returned to the atmosphere by:
--> burning of carbon containing substances (fossil fuel)
--> respiration of plants and animals and
--> Decomposition of organic substances.
Therefore the role of fossil fuels which are rich in carbon content releases carbon into the atmosphere when burnt.
Identify the formula for ammonium nitrate
(NH4)3NO3
NH4(NO2)2
NH4NO2
Answer:
NH₄NO₃
Explanation:
In salt naming, the cation is named first, then you must put the name of the anion. In the same way when you are writting the formula. Also, the global charge of a salt is always 0.
Thus, we must write each ion and its charge:
Ammonium: NH₄⁺
Nitrate: NO₃⁻
As both ions have the same charge, the formula is:
NH₄NO₃The cation first and then the anion.
Covalent bonds can be single, double, or triple.
How many electrons are shared in a molecule, like O2 that has a double bond?
4
6
12
2
How to calculate the mass of the sulfur (VI) oxide molecule
Explanation:
If you look back at the formula ( SO2 ), you can see that there is one sulfur and two oxygens present. Therefore, the molar mass of sulfur dioxide is [1 × 32.1 + 2 × 16.0] = 64.1 g/mol.
Which statement describes the motion of the sun?
The sun rotates at the same rate throughout.
The sun does not rotate at its poles.
Different parts of the sun rotate at different rates.
The sun does not rotate at its equator.
Answer: Different parts of the sun rotate at different rates.
Explanation:
The statement that best describes the motion of the sun is that different parts of the sun rotate at different rates.
First and foremost, we should note that the rotation of the sun is on its axis and also the sun isn't a solid. Due to this, its motion will be that there'll be rotation of different part of it at different rates. Assuming the sun was solid, then all of its parts will move together.
Answer:
Different parts of the sun rotate at different rates.
Explanation: pic proof
Which isotopic ratio needs to be determined
when the age of ancient wooden objects is
investigated?
(1) U-235 to U-238 (3) N-16 to N-14
(2) H-2 to H-3
(4) C-14 to 6-12
Answer: (4) C-14 to 6-12
Explanation:
Carbon dating is used to estimate the age of wooden trees which use carbon dioxide. Carbon has three naturally occurring isotopes.C-12 and C-13 are stable but C-14 is radioactive. C-14 decays to nitrogen-14 and has a half-life of 5,730 years.
Wooden trees naturally incorporate both the C-12 and C-14 during their lifetimes. When wooden trees die, it stops consuming more of radioactive carbon while the C-14 which is already present in them continues to decay back into nitrogen. With the help of C-12 to C-14 ratio, we can estimate the age of wooden objects.
The age of ancient wooden objects is investigated using the C-14 to C-12.
Carbon dating provides an effective way to determine the age of a sample. The idea here is that all living organisms give out C-14 while they are alive and the amount of the isotope in a living sample is known.
The age of a sample is obtained by comparing the level of the C-14 isotope present in it to the amount present in a living tissue. Hence, the age of ancient wooden objects is investigated using the C-14 to C-12.
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Identify one trait in a plant that could be changed with selective breeding and explain how the change would be useful? Science. I will give brainliest to people who answer correctly
Write the name for the IONIC compound that contains two aluminum atoms and three sulfur atoms. (Need help ASAP)
What energy transform occurs when the hot plate is plugged into the outlet and the control knob is on position?
Thermal to mechanical
Thermal to electrical
Electrical to thermal
Mechanical to thermal
Answer:
Its electrical to thermal energy
Explanation:
Which is a property of potassium (K)?
A. It is dull and brittle.
B. It is extremely reactive.
C. It is not reactive.
D. It is white and hard.
Answer:
B: It is extremely reactive
Explanation:
Potassium metal is also soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity.
Answer: Properties, occurrence, and uses. Potassium metal is soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity. Potassium imparts a lavender colour to a flame, and its vapour is green.
Explanation: hope it helps
how is a waves amplitude related to the amount of energy the wave carries?
Answer:
The energy transported by a wave is directly proportional to the square of the amplitude. So whatever change occurs in the amplitude, the square of that effect impacts the energy. This means that a doubling of the amplitude results in a quadrupling of the energy.
Explain why the answer is correct and why the others aren’t.
Pleaseeee
Answer:
Buffalo and Watertown.
Explanation:
This is correct as the Interior lowlands are located ib the US. These are correct as the others are in the US but aren't located anywhere near the Interior Lowlands.
Which of the followiing is not a principle of natural selection?
Plss answer the question in the picture.
Consider the diagram. Top: A ball is shown traveling left to right toward an identical stationary ball. Middle: the first ball hits the second ball. Bottom: The right-hand ball travels to the right away from the left-hand ball, which is now stationary.
Which postulate of the kinetic-molecular theory best describes the event in the diagram?
Most of the volume of a gas is empty space.
All collisions between particles are perfectly elastic.
There is no force of attraction or repulsion between gas particles.
The average kinetic energy of particles depends only on temperature.
Answer:
All collisions between particles are perfectly elastic
Explanation:
found it somehwere else
The statement, that describes postulate of the kinetic-molecular theory is "all collisions between particles are perfectly elastic."
What is collisions?A collision would be any process where two or even more objects exert forces on one another quickly.
What is kinetic-molecular theory?The kinetic-molecular theory explains matter states and is based on the assumption that matter is made up of small particles that are always in motion. It is a simple, historically significant classical model of the thermodynamic behavior of gases that established several fundamental thermodynamic ideas.
Because the molecules are so small, the kinetic theory of gases assumes that the collision between them is fully elastic. Because the molecules are so small, their energy and momenta are conserved during collisions. As a result, regardless of collisions, the temperature remains constant.
Hence the correct option is all collisions between particles are perfectly elastic.
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What would be the answer for these?
1. 4
2. 4
3. 2
4. 2
Further explanationGiven
Reaction
2H₂+O₂⇒2H₂O
Required
Number of atoms
Solution
In compounds, the number of atoms of the constituent components in the form of elements is usually indicated by a subscript after the element symbol, while the number in front of the compound which is the coefficient indicates the number of molecules of the compound.
In chemical reactions, the reactants are on the left and the products on the right
1. Number of Hydrogen in reactants
2 molecules x 2 atoms = 4 atoms
2. Number of Hydrogen in products
2 molecules x 2 atoms = 4 atoms
3. Number of Oxygen in reactants
1 molecules x 2 atoms = 2 atoms
3. Number of Oxygen in products
2 molecules x 1 atoms = 2 atoms
The reaction is said to be balanced because the number of atoms of the element is the same between the reactants and products
4.0 moles of H2O would have what mass?
Group of answer choices
18 g
23 g
68 g
72 g
Answer:
How many moles H2O in 1 grams? The answer is 0.055508435061792.
We assume you are converting between moles H2O and gram.
You can view more details on each measurement unit:
molecular weight of H2O or grams
This compound is also known as Water or Dihydrogen Monoxide.
The SI base unit for amount of substance is the mole.
1 mole is equal to 1 moles H2O, or 18.01528 grams.
Explanation:
The mass of 4.0 moles of water is 72 grams.
Explanation:
Moles of the substance is equal to the ratio of the mass of substance to the molar mass of the substance:[tex]Moles=\frac{\text{mass of substance}}{\text{molar mass of substance}}[/tex]
Given:
The 4.0 moles of water
To find:
Mass of moles of water
Solution:
The moles of water = 4.0 moles
The mass of water = M
The molar mass of water = 18.01528 g/mol
[tex]4.0=\frac{m}{ 18.01528 g/mol}\\m=4.0\times 18.01528 g/mol\\=72.06112 g\approx 72 g[/tex]
The mass of 4.0 moles of water is 72 grams.
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