Answer:
[tex]\boxed {\boxed {\sf 2.29 *10^{24} \ atoms \ Ca}}[/tex]
Explanation:
To convert from moles to atoms, we must use Avogadro's Number.
[tex]6.022*10^{23}[/tex]
This number tells us the number of particles (atoms, molecules, ions, etc.) in 1 mole. In this case, the particles are atoms of calcium (Ca).
[tex]6.022*10^{23} \ atoms \ Ca / 1 \ mol \ Ca[/tex]
1. Convert from moles to atoms.
Write Avogadro's number as a fraction.
[tex]\frac {6.022 *10^{23} \ atoms \ Ca} {1 \ mol \ Ca}[/tex]
Multiply the given number of moles of calcium (3.8) by the fraction created.
[tex]3.8 \ mol \ Ca *\frac {6.022 *10^{23} \ atoms \ Ca} {1 \ mol \ Ca}[/tex]
The moles of calcium will cancel.
[tex]3.8 *\frac {6.022 *10^{23} \ atoms \ Ca} {1 }[/tex]
The denominator of 1 is insignifcant and we can turn this into a simple multiplication problem.
[tex]3.8 * {6.022 *10^{23} \ atoms \ Ca}[/tex]
[tex]2.28836*10^{24} \ atoms \ Ca[/tex]
2. Round
The problem tells us to round to 2 decimal places or the hundredth place.
[tex]2.28836*10^{24} \ atoms \ Ca[/tex]
The 8 in the thousandth place tells us to round the 8 to a 9.
[tex]2.29 *10^{24} \ atoms \ Ca[/tex]
There are about 2.29*10²⁴ atoms of calcium in 3.8 moles.
How might the information on melting point, boiling point, and flammability be useful to materials scientists
The information on melting point, boiling point, and flammability might be useful to materials scientists as:
What is Melting point?The temperature for the pure substance at which the liquid and solid phase exist in equilibrium condition
What is Boiling point?The temperature at which the vapour pressure of the liquid is equal to the atmospheric pressure.
What is flammability?Flammability is the ability of a substance such as solid, liquid and gases to ignite in air if source of ignition is applied.
Material scientist apply the knowledge of physical and chemical properties of different compounds to synthesize new product or improve existing ones.
Hence to know the knowledge about melting point, boiling point, flammability might be necessary conditions for material scientist.
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What is oxydation number of s for H2S ? ( hydrogen sulphide )
Answer:
the oxidation number is zero because H=+1. S=-2
Explanation:
so two hydrogen and one sulphur so total no is zero
what is the mass of of 3.20 X 10^23 particles of Co2?
Answer:
Mass = 23.36 g
Explanation:
Given data:
Number of particles of CO₂ = 3.20 ×10²³
Mass of CO₂ = ?
Solution:
1 mole contain 6.022×`10²³ particles,
3.20 ×10²³ particles × 1 mol / 6.022×`10²³ particles
0.531 mol
Mass of CO₂:
Mass = number of moles × molar mass
Molar mass = 44 g/mol
Mass = 0.531 mol× 44 g/mol
Mass = 23.36 g
Which of the elements has the same Lewis dot structure as calcium (Ca)?
A.Barium (Ba)
B.Potassium (K)
C.Germanium (Ge)
D.Argon (Ar)
Answer:
[tex]\boxed {\boxed {\sf A. \ Barium (Ba)}}[/tex]
Explanation:
Lewis dot structures illustrate the valence electrons in an element.
Valence electrons are the outermost electrons in an atom that bond with other atoms by accepting or releasing electrons. The groups, or columns, of the Periodic Table have the same number of valence electrons.Calcium is in group 2.
The other elements in this group are:
Beryllium, Magnesium, Strontium, Barium, and RadiumSo, all these elements have the same lewis dot structures because they have the same number of valence electrons.
Based on the answer choices, choice A is correct.
2) If I have an unknown quantity (# of moles) of gas at a pressure of 32 atm, a volume of 70 L, and a temperature of 25˚C. How many moles of gas are in the sample?
Answer:
91.5 mol
Explanation:
Volume of gas = 70 L
Temperature = 25°C
Pressure = 32 atm
Moles of gas = ?
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
25+273.15 = 298.15 K
By putting values,
32 atm × 70 L = n ×0.0821 atm.L /mol.K × 298.15 K
2240 atm.L = n ×24.48 atm.L /mol
n = 2240 atm.L / 24.48 atm.L /mol
n = 91.5 mol
Please help me, Thank you!
Answer:
2
Explanation:
The atom shown in the image has 2 core electrons.
Electrons are the negatively charged particles within an atom. Therefore the total number of electrons surrounding the nucleus in the given specie is 7.
So;
We have 2 core electrons
And 5 valence electrons
The core electrons are the inner orbital electrons.
The valence electrons are the outermost electrons.
The photo shows a frozen juice pop on a hot day.
Which detail could be added to the photo to model the thermal energy
transfer that is taking place?
A. Arrows pointing from the juice pop to the sun
B. Arrows pointing from the persons hand to the juice pop
C. Circles with arrows on the top of the juice pop
D. Arrows pointing from the sun to the juice pop
Answer:
C! Hope this helps !:)
Explanation:
Answer:
Arrows pointing from the sun to the juice pop
Explanation: Trust I got it right
Which of the following is a necessary product of a combustion reaction?
A. A precipitate
B. Heat
C. A hydrocarbon
D. Oxygen
Answer:
B. Heat
Have a nice day everyone!
To solve such this we must know the concept of combustion reaction. Therefore, heat is a necessary product of a combustion reaction. The correct option is option B.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Combustion reaction is a reaction in which a substance, basically hydrocarbons burns in presence of oxygen to produce carbon dioxide and water and heat in huge amount.
Therefore, heat is a necessary product of a combustion reaction. The correct option is option B.
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Which describes a similarity between abiotic and biotic Which describes a similarity between abiotic and biotic factors?
A.They may include things that were once living.
B.They are both necessary for organisms to survive.
C.They are not usually important parts of the environment.
D.They can be easily replaced if they are used or destroyed.factors?
option A is correct.biotic is a nother word for living
Answer:
option A would be the correct answer for the question below.
Explanation:
Which describes a similarity between abiotic and biotic factors?
A chef is cooking with a 2000-gram stainless steel skillet. Stainless steel has a specific heat capacity of 0.450 J/(g *oC). How much heat energy is required to raise the temperature of the skillet from 25oC to 125oC?
Group of answer choices
44,000 Joules
90,000 Joules
22,500 Joules
855 Joule
Answer:
Q = 90,000 J
Explanation:
Given data:
Mass skillet = 2000 g
Specific heat capacity = 0.450 J/g.°C
Energy required to raise temperature = ?
Initial temperature = 25°C
Final temperature = 125°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 125°C - 25°C
ΔT = 100°C
Q = 2000 g × 0.450 J/g.°C × 100°C
Q = 90,000 J
a toy car is pushed forward with a force of 5N. Air resistance and friction apply a combined force of 3.5N backwards, what is the resultant force
Answer:
Hi... U should do like this
5 - 3.5=1.5 (N)
what are the parts of a chemical change
Answer:
These include decomposition, synthesis, displacement, acid-base, combustion, oxidation-reduction, electrochemical
Answer:
Chemical Reaction Parts:
These include decomposition, synthesis, displacement, acid-base, combustion, oxidation-reduction, electrochemical, and myriad others.
Explanation:
Seven Things That Indicate a Chemical Change Is Occurring
Gas Bubbles Appear. Gas bubbles appear after a chemical reaction has occurred and the mixture becomes saturated with gas. ...
Formation of a Precipitate. ...
Color Change. ...
Temperature Change. ...
Production of Light. ...
Volume Change. ...
Change in Smell or Taste. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding. Often, physical changes can be undone, if energy is input.
How are the electron structures of boron (B) and aluminum (Al) similar?
A. They both have valence electrons in the second energy level.
B. They both have 3 electrons in each sublevel.
C. They both have 1 electron in a p orbital.
D. The highest sublevel that has electrons is the 3p sublevel.
my brain isn't functioning correctly. 2 days up working on homework lol
Answer:
C: They both have 1 electron in a p orbital.
Explanation:
Find the electron configuration of B
Boron is 1s 2s2 2p1
Find the electron configuration of Al
Aluminum is 1s2 2s2 2p6 3s2 2p1
If you look at the p orbital, they both have 1 electron.
Therefore, the correct answer is C.
Hope it helped!
13. Think about the noble gases.... *
Answer:
Its C - He
Explanation:
Which is true of scientific questions?
A. Few scientific questions lead to useful investigations.
B. Scientific questions are answered by doing experiments.
C. Many scientific questions are too complex to be tested.
D. Scientific questions are biased by the opinions of scientists.
An ionic bond is a bond that forms between
A. ions with opposite charges
B. atoms with neutral charges
C. one atom's nucleus and another atom's electrons
D. the electrons of two different atoms
Answer:
A. ions with opposite charges
Explanation:
Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.
What are all the elements in a column called? NO LOOKING IT UP and if u do put it in ur words
Answer:
There have been seven horizontal rows of elements are called phases in the periodic table of elements. Groups, or families, are called vertical columns of elements. Metals, – anti, and metals are the most common ways of classifying the periodic table.
Explanation:
In addition or subtraction, the result carries the same number of decimal places as the quantity carryi
the fewest decimal places.
Using the expression Ka=[H+][A−][HA] , explain how to determine which solution has the lower pH , 0.10MHF(aq) or 0.10MHC2H3O2(aq) . Do not perform any numerical calculations.
Answer:
0.10MHF(aq)
Explanation:
Given that:
[tex]K_a = \dfrac{[H^+][A^-]}{HA}[/tex] , to find the solution with a lower pH between 0.10MHF(aq) or 0.10MHC2H3O2(aq).
Recall that:
The higher the Ka value, the higher the ionization, hence more formation of protons in the solution. Also, higher H⁺ in solution results in a lower pH value.
Since HF have a higher Ka value, then HF solution will have a lower pH.
The acidity and alkalinity measure of a substance based on hydroxyl or hydrogen ion released is called pH. It is measured based on the pH scale that tells about the acidity and basicity of the substance.
0.10 M [tex]\rm HF[/tex] (aq) has lower pH.
The pH can be explained as:The acid dissociation constant ([tex]\rm K_{a}[/tex]) is given by,
[tex]\rm K_{a} = \dfrac{[H^{+}][A^{-}]}{[HA]}[/tex]
The value [tex]\rm K_{a}[/tex] of can be used for determining the lower and higher pH.When the [tex]\rm K_{a}[/tex] value is high then the ionization of the substance will be higher resulting in the release of more protons in the solution.When [tex]\rm H^{+}[/tex] is high then the pH will be lower and the solution will be more acidic.The [tex]\rm K_{a}[/tex] value of [tex]\rm HF[/tex] is more compared to the [tex]\rm HC_{2}H_{3}O_{2}[/tex] resulting in lower pH and more acidity.Therefore, 0.10 M [tex]\rm HF[/tex] (aq) has lower pH.
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Uranium contains two isotopes, U-235 with an atomic mas of 235 g/mol, and u-238 with an atomic mass of 238g/mol. U-235 is needed
as a fuel in nuclear reactors. Until recently, the method used to separate U-235 from U-238 was by gas diffusion. Use U-235 as R1, and
U-238 as R2 and determine the rate of diffusion and which gas will diffuse faster.
⚪︎U-235 diffused 10.01 times faster than U-238
⚪︎U-235 diffused 1.01 times slower than U-238
⚪︎U-235 effused 2.01 times slower than U-238
⚪︎U-235 effused 1.01 times faster than U-238
⚪︎U-235 diffused 1.01 times faster than U-238
Answer:
the answer is in the image
Explanation:
When an electron moves from a lower energy level to a higher energy level, the atom:
A. absorbs light
B. gives off light
C. becomes a new isotope
Answer:
A. absorbs light
Explanation:
For an electron to move from a lower energy level to a higher energy level, energy needs to be added to the atom.
In most cases this required energy will be light: The electron of the atom will absorb the energy of the light and move to a higher energy level.
When said electron comes back to the lower energy level, the atom will conversely give off light.
What is the percent abundance of Pt-196, if the average atomic mass of platinum is 195.16 and platinum has only four naturally
occurring isotopes?
A)
8%
B)
25%
33%
D)
50%
The answer is 25%
Which of the following is not a unit of volume? (A) L (B) mL (C) m3 (D) cm2
HELP PLS IT DUE TODAY!!!!!
Answer: Choice D) cm^2
This is the same as saying "square cm". This is a unit of area, and not a unit of volume. Consider a 1 cm by 1 cm square. It's area is 1 square cm. As another example: a rectangle with sides 7 cm by 14 cm has area 14*7 = 98 cm^2.
Much like how 5*5 = 5^2, we apply this idea to the units which is why cm*cm = cm^2.
The ability of iron to conduct electricity is a physical property of iron. *
True
False
Answer:
True
Explanation:
A physical property is a property that can be measured without changing the chemical composition of the substance.
The chemical composition of iron does not change when it conducts electricity so conductivity is a physical property.
Hope that helps.
Atoms of different element can not have same atomic number because only same type of atoms combine to form element. Atoms belonging to different element can have different atomic number. Therefore, the given statement is true.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same. Two or more than two atoms with different physical or chemical properties can not combine together to form an element.
A physical property is a property that can be measured without changing the chemical composition of the substance. So, ability of iron to conduct electricity is a physical property of iron
Therefore, the given statement is true.
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How many moles of oxygen are required to produce 12 moles of water?
Answer:
6 moles of Oxygen required
Answer:
6
Explanation:
I hope this helps with your question :)
2. Which pair of elements would have the greatest difference in electronegativities? *
Answer:a
Explanation:
During ________________________, a new nuclear membrane forms around eachgroup of chromosomes.
Answer:
Telophase
Explanation:
I looked up the ending lol!hope this helps
If a 10 kg stone falls from a height of
30 m, what is the velocity of the stone
as it hits the ground?
Answer:
26.32 because z easy
Explanation:
Answer:
26.32 because z easy
Explanation:fds
Answer:
26.32 becfdseefdause z easy
Explansefdsefdsefdsenfuystyegfsvfgvsfhs76ieu4fguyhgvrykes4rjehrfgehg4fuebecause z easy
Explanasetion:sf
26.32 because z easy ef
Explanation:
Answer:ds
26.32 because z easy
Explanation:
hbdshfiushyAnswer:
26.32 because z easy
Explanation:
Answer:
26.32 because z easy
Explanation:fds
Answer:
26.32 becfdseefdause z easy
Explansefdsefdsefdsenfuystyegfsvfgvsfhs76ieu4fguyhgvrykes4rjehrfgehg4fuebecause z easy
Explanasetion:sf
26.32 because z easy ef
Explanation:
Answer:ds
26.32 because z easy
Explanation:
hbdshfiushy
I need help please help me !
Answer:
the rust formed because of the water sitting in sied a metal bowl for long time but they can fix this if they get filters
Explanation:
How many moles are in 3.63 x 1023 atoms of Mn?
Answer:
0.603 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.63 \times {10}^{23} }{ 6.02 \times {10}^{23} } = \frac{3.63}{6.02} \\ = 0.60299...[/tex]
We have the final answer as
0.603 molesHope this helps you
