Answer:
The change was physical, meaning it went from liquid to solid, or the other way around.
Explanation:
This is about change in substances.
Physical Change took place.
There are two major changes in chemistry. They are;- Physical changes: These are changes where no new substances are formed but only undergoes change of state.
- Chemical changes: These are changes where new substances are formed.
Now, for crayon and candle to be cooled, it means they were heated.Now when we heat either crayon or candle, we initially see it melting with a liquid like substance flowing down. Thereafter, when cooled, they become solid again.
In all these, no new substance was formed as they just only changed from solid to liquid and back to solid.This is what physical change is all about.
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i’m so lost please help
C=4
D=-19
Explanation:
2exp-25/5exp-7= 4exp-19
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
To learn more about the Periodic table, refer to the link:
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How many moles of precipitate will be formed when 100.0 mL of 0.200 M NaBr is reacted with excess Pb(NO₃)₂ in the following chemical reaction?
2 NaBr (aq) + Pb(NO₃)₂ (aq) → PbBr₂ (s) + 2 NaNO₃ (aq)
Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
Explanation : Given,
Concentration of NaBr = 0.200 M
Volume of solution = 100.0 mL = 0.1 L (1 L = 1000 mL)
First we have to calculate the moles of NaBr.
[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]
[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]
Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.
The balanced chemical reaction is:
[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]
From the balanced chemical reaction we conclude that:
As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]
So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]
Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole
We'll begin by calculating the number of mole of NaBr in 100 mL of 0.2 M NaBr solution. This can be obtained as follow:Volume = 100 mL = 100 / 1000 = 0.1 L
Molarity of NaBr = 0.2 M
Mole of NaBr =?Mole = Molarity x Volume
Mole of NaBr = 0.2 × 0.1
Mole of NaBr = 0.02 mole Finally, we shall determine the number of mole of the precipitate (i.e PbBr₂) produced from the reaction. This can be obtained as follow:2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)
From the balanced equation above,
2 moles of NaBr reacted to produce 1 mole of PbBr₂.
Therefore,
0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.
Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole
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Which element is classified as a noble gas?
Answer:
The elements with completely filled shells are classified as noble gases
That is why we only see noble gases on the rightmost corner of the periodic table, it is because they have the maximum number of electrons in a shell
Examples of noble gases
Helium , Neon , Argon and Krypton are some examples of noble gases
Answer:
D. (Xe) XenonExplanation:
I JUST TOOK THE TEST!
4. This is low wet land.
A. swamp
B. island
C. desert
D. peninsula
5. Japan is one of these.
A. island
B. peninsula
C. swamp
D. desert
Answer:
swap
Explanation: because it is a low wet land
Answer:
4. swamp
5. Island
Plz mark brainliest:)
Please help me!!!:)))
Answer:
blocks 1 and 2 the rhdh huff hgfhh5
What can you infer about the likely occurrence of the other isotopes in each of the
above elements? Explain your reasoning.
Answer:
Most common has the same or closest mass because it is closer to the original’s mass.
Explanation:
I got it from the answer key
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Hereditary information is passed on from:
O nucleus to nucleus
O cell to cell
O cell to nucleus
O nucleus to cell
Answer:
D - Nucleus to Cell
Explanation:
Hope it helps!!
:D
8. Why is the magnetic force considered to be a noncontact force?
Answer:
Magnetic forces are non contact forces; they pull or push on objects without touching them. Magnets are only attracted to a few 'magnetic' metals and not all matter. Magnets are attracted to and repel other magnets.
Hope this helps!!!
Explanation:
Express the following numbers in scientific notation:
872
Answer:
The number 872 would be written as,
8.72× 10²
Explanation:
Scientific notation is used to express the large value in short form.
The number in scientific notation have two parts.
First part:
The digits (decimal point will place after first digit)
Second part:
× 10 ( the power which put the decimal point where it should be)
For example the number 872 would be written as
8.72× 10²
Another example:
6324.4 in scientific notation will be written as = 6.3244 × 10³
HELP PLEASE, IM ON A TIMER ⏱
Which describes an attribute of nonrenewable resources?
A.) exist in fixed amounts
B.) are unlimited
C.) can often be replaced in a short time
D.) are replaced faster than they are used
Answer:
A. exist in fixed amounts or available in limited supplies
Explanation:
Answer:
A
Explanation:
__________ 5. Chemical equilibrium is the result of A. all of the reactants being converted into products. B. stoppage of further reaction. C. formation of products equal in mass to the mass of the reactants. D. opposing reactions attaining equal rates. E. a loss of pressure in the system.
Answer:
The correct option is C
Explanation:
Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.
I don't know what category to put this question in, but I attached a photo of it. Can someone please help me answer it?
Analysing the question:
To calculate the density of a material, we need its mass and volume
We are given:
Mass of sample = 21 grams
dimensions of the sample = 1 * 1 * 2 = 2 cm³
Calculating the density:
Density = Mass of sample / volume of sample
Replacing the variables
Density = 21 / 2
Density = 10.5 g / cm³
Determining the Material:
From the table provided, we can see that the density of Silver is 10.5 g/cm³
Therefore, the material is Silver
Determine the volume of 15.5 g of a substance with a density of 6.89 g/ml
Answer:
The answer is 2.25 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question
mass = 15.5 g
density = 6.89 g/mL
We have
[tex]volume = \frac{15.5}{6.89} \\ = 2.249637155...[/tex]
We have the final answer as
2.25 mLHope this helps you
Y-Chart
Explain how an invasive species can influence each aspect of an ecosystem.
Answer:
Invasive species are an organism that causes ecological or economic harm in a new environment where it's not native.
Explanation:
An invasive species can harm both the natural resources in the ecosystem as well it threaten the human use of these resources and invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and etc.
Invasive species is capable of causing extinctions to native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can also result a huge economic impacts and fundamental disruptions of coastal and the great lakes of the ecosystems.
I hope it helps you.
Cementation is part of the process of
A. igneous intrusion
B. lithification
C. igneous extrusion
D. metamorphism
SUBMIT
Answer:
The correct answer is b.
Explanation:
hope this helps u
Answer:
Bryna is correct it is B
Explanation:
If equal volumes of a strong base and a weaker acid are mixed together, what would you expect the pH of the resulting salt to be
Answer:
Above 7
Explanation:
The equivalence point of any titration can be read off from the appropriate titration curve.
A titration curve is a plot of the pH of analyte against the volume of titrant added.
For a strong base and weak acid, the equivalence point lies above 7.
The pH of the resulting salt to be pH> 7 .
What does Equivalence point tell?The equivalence point of any titration can be read off from the appropriate titration curve. A titration curve is a plot of the pH of analyte against the volume of titrant added. It is a point in titration at which the amount of titrant added is just enough to completely neutralize the analyte solution. At the equivalence point in an acid-base titration.
For a strong base and weak acid, the equivalence point lies above 7.
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‘ASAP’What do the different categories of hurricanes represent?
O Air density
O Humidity
O Pressure
O Wind speeds
Answer:
Sorry I do not know the answer but I do know its not c (pressure)
Explanation:
I took a quiz with that question and I got it wrong my other guess is air density though
Answer:
Wind Speeds
Explanation:
im awnsering late cuz i need pointsss
what does celery, a wooden spoon, and oil/gasoline have in common?
Answer:
All of them are organic compounds which have carbon as their main atom in the structure.
Explanation:
Hello.
In this case, since organic chemistry is the study of all the compounds having the carbon atom as their main atom, all the vegetables, animals, an in general, living things are composed by lipids, proteins, and other organic substances with this feature. Moreover, wood-based materials are mainly composed by lignin which is an organic polymer also having carbon as the main atom. In addition, oil and gasoline are organic chemical compounds with a lot of applications in daily life which also contain carbon atoms in their structure.
In such a way, a celery, a wooden spoon, and oil/gasoline have the carbon atom in common as their main atom in their chemical structures.
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PLEASE HELP AND FAST!!!
using this chemical might discolour equipment and surfaces
Answer: do not know how to answer this
Explanation:
How many elements are in calcium dihydrogren phosphate
1. Marisa determined the melting point of a substance to be 24.5C. Find the percent error of her measurement if the actual melting point is 31.2C.
Answer:
[tex]\%\ Error = 21.5\%[/tex]
Explanation:
Given
[tex]Measured = 24.5[/tex]
[tex]Actual = 31.2[/tex]
Required
Determine the percentage error
First, we need to determine the difference in the measurement
[tex]Difference = |Actual - Measured|[/tex]
[tex]Difference = |31.2 - 24.5|[/tex]
[tex]Difference = |6.7|[/tex]
[tex]Difference = 6.7[/tex]
The percentage error is calculated as thus:
[tex]\%\ Error = \frac{Difference * 100\%}{Actual}[/tex]
[tex]\%\ Error = \frac{6.7 * 100\%}{31.2}[/tex]
[tex]\%\ Error = \frac{670\%}{31.2}[/tex]
[tex]\%\ Error = 21.4743589744\%[/tex]
[tex]\%\ Error = 21.5\%[/tex] approximated
The initial pressure of a mixture of C6H6 and an excess of H2 in a rigid vessel is 1.21 atm. A catalyst is introduced. After the reaction reaches completion, the temperature is restored to its initial value. The final pressure in the vessel is 0.839 atm. What was the mole fraction of C6H6 in the original mixture
Answer:
mole fraction of C6H6 = 0.613 atm
Explanation:
The equation for this reaction is :
[tex]C_6H_6 _{(g)} + 3H_2_{(g)} \to C_6H_{12}_{(g)}[/tex]
Initial P₁ P₂ 0
Final 0 P₂ -P₁/2 P₁
After completion of the reaction;
P₁ + P₂ = 1.21 atm ----- (1)
P₂ - P₁/2 + P₁ = 0.839 atm
P₂ + P₁/2 = 0.839 atm ----- (2)
Subtracting (2) from (1); we have:
P₁/2 = 0.371
P₁ = 0.742 atm
From(1)
P₁ + P₂ = 1.21 atm
0.742 atm + P₂ = 1.21 atm
P₂ = 1.21 atm - 0.742 atm
P₂ = 0.468 atm
Thus, the partial pressure of C6H6 = 0.742 atm
∴
Partial pressure = Total pressure × mole fraction of C6H6
mole fraction of C6H6 = Partial pressure / Total pressure
mole fraction of C6H6 = 0.742 atm / 1.21 atm
mole fraction of C6H6 = 0.613 atm
How many grams of NO2 would be formed from 1.0 mole of NO and excess of O2?
Answer:
Mass = 46 g
Explanation:
Given data:
Number of moles of NO = 1.0 mol
Amount of O₂ = excess
Mass of NO₂ formed = ?
Solution:
Chemical equation:
2NO + O₂ → 2NO₂
Now we will compare the moles of No with NO₂.
NO : NO₂
2 : 2
1 : 1
Mass of NO₂ in gram:
Mass = number of moles × molar mass
Mass = 1 mol ×46 g/mol
Mass = 46 g
A student asks why the ashes from a fire have a much lower mass than the wood that was burned.
Which is the correct answer to the student’s question?
Gases are released into the air.
Atoms in the wood are destroyed.
Heat causes the molecules to change color.
Water inside the wood solidifies.
(I am not in college)
__________ have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Answer: have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Explanation:
What does a dissolved salt look like?
Answer:(trick question) once the salt has dissolve in the water it is no longer visible
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True or False: All cells have different basic chemical composition. *
True
False
plsss help!!!!! I'll give u brainlest and 10 points
Answer:
I would say it is true
Explanation: