Please help is for my final An example of a chemical change is-
evaporation of seawater
о
sublimation of dry ice (CO2)
melting of aluminum
burning wood reducing it to ashes
Explanation:
Souring of milk
Baking of cake
Describe and show an example of valence electrons. What is a common trend you can remember to help you understand valence electrons?
Explanation:
valency from right to left in a Periodic Table in same period first increases then decreases and from top to bottom it is same for a same group
A man needs to lift a heavy box on the back of a truck or push up a ramp or lift it straight up from the ground to use around he won't have to move the box over a longer distance what did is the benefit of using a ramp to get the box
The equilibrium of 2H2O(g) 2H2(g) + O2(g) at 2,000 K has a Keq value of 5.31 x 10-10. What is the Keq expression for this system?
A) [H2}^2[O2} / [H2O]^2
B) [H2][O2] / [H2O]
C) [H2O]^2 / [H2]^2[O2]
D) [H2O]^2 / [H2][O2]
Answer:
B
Explanation:
I don't know how to explain this but you get it
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)
what is zinc chemical formula?
Answer:
Zn+2
Explanation:
I'm sorry if its wrong but have a good one!
When two atoms form a molecule, the molecule has lower energy than the two separate atoms. However, when only two atoms are present, they bounce off each other and do not form a molecule. Explain what happens to the energy of the atoms when there are only two atoms and they collide.
DONT GIVE ME A LINK!!
Answer:
they end up bouncing against each other instead of merging together
Explanation:
PLZ SOMEONE HELP I’LL MARK AS BRAINLIEST!!!
In an experiment 10 grams of a substance has a volume of 24 cm? What is the
substances' density ?
Answer:
[tex]d=0.417\ g/cm^3[/tex]
Explanation:
Given that,
Mass, m = 10 g
Volume, V = 24 cm³
We need to find the density of the substance. We know that, the density of a substance is given by :
Density = mass/volume
So,
[tex]d=\dfrac{10\ g}{24\ cm^2}\\\\d=0.417\ g/cm^3[/tex]
So, the density of the substance is [tex]0.417\ g/cm^3[/tex].
A substance has a boiling point of 78 °C. Which of the following is true about the substance? (5 points) a It will also change from a gas to a solid at 78 °C while the gas loses energy. b It will also change from a gas to a solid at 78 °C while the gas gains energy. c It will also change from a gas to a liquid at 78 °C while the gas loses energy. d It will also change from a gas to a liquid at 78 °C while the gas gains energy.
Answer: If a substance has a boiling point of [tex]78^{o}C[/tex] then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
Explanation:
The temperature at which vapor pressure of a liquid substance becomes equal to the atmospheric pressure is called boiling point of substance.
At the boiling point, liquid phase and vapor phase remains in equilibrium.
This means that as liquid phase changes into vapor phase and also vapor phase changes into liquid phase at the boiling point.
Thus, we can conclude that if a substance has a boiling point of [tex]78^{o}C[/tex] then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
HURRY PLEASE
What volume is occupied by 3.12 moles of a gas when the pressure is 88.4 kPa at a temperature of 19℃?
Answer:
The Combined Gas Law shows that the pressure of a gas is inversely proportional to volume and directly proportional to temperature. Avogadro's Law shows that volume or pressure is directly proportional to the number of moles of gas. Putting these together leaves us with the following equation:
P1×V1T1×n1=P2×V2T2×n2(11.9.1)
As with the other gas laws, we can also say that (P×V)(T×n) is equal to a constant. The constant can be evaluated provided that the gas being described is considered to be ideal.
The Ideal Gas Law is a single equation which relates the pressure, volume, temperature, and number of moles of an ideal gas. If we substitute in the variable R for the constant, the equation becomes:
P×VT×n=R(11.9.2)
The Ideal Gas Law is conveniently rearranged to look this way, with the multiplication signs omitted:
PV=nRT(11.9.3)
The variable R in the equation is called the ideal gas constant.
Explanation:
If the half-life of a decaying isotope is 10 years, which statement is true after
20 years?
Answer:
A. There are more daughter nuclei than parent nuclei in a sample.
Explanation:
There are more daughter nuclei than parent nuclei in a sample. Hence, option A is correct.
What is half-life?The half-life of a radioactive element or isotope is the time taken for half of the substance to decay.
If the half-life of a decaying isotope is 10 years, after 8 years, less than the total mass of the original isotope will decay since 8 years is less than 10 years.
Therefore, we can conclude that, if the half-life of a decaying isotope is 10 years, after 8 years, there will be more parent nuclei than daughter nuclei in a sample.
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What are some of the issues facing the ocean ( give at least 3 )
Answer:
Pollution
Overpopulation
Destruction of habitats
Explanation:
If a book has a weight of 23.2 N on Earth, what is its mass?
Answer: Mass is 2,37 kg
Explanation: Weight G = mg, and g = 9.81 m/s² on Earth.
m = W/g = 23.2 N / 9.81 m/s²
Which of the following can be used to measure an object's
speed?
Answer:
distance traveled divided by the time it traveled
Explanation
this is just an equation for how to find speed. you can also just use like a meterstick and a stopwatch
M
Mass can be measured in local units like dharni pau eto. Discuss the advantages of using
standard units of mass over the local units of mass. (Any two points)
N2 Points)
soup answer
Answer:
1.They are reliable.
2.They dont vary from person to person
Why are shadows shorter around noon?
Make sure you give a full, detailed answer, not just one sentence.
Answer: Answer is in the Explanation.
Explanation: At noon the sun is directly above in the sky, the sun's rays are falling on the body making the shadow smaller. While in the evenings and mornings the sun is at a inclined position, so the sun's rays are falling at a inclined position making the body's shadow larger.
I looked it up on the internet and reworded it as good as I could.
Which best describes the purpose of a fever?
Answer:
when you have a fever your body is trying to fight off a virus or some other kind of bad Bacteria
Explanation:
I think this because everyone has at least had a fever when they were sick and when you are sick you are likely to have a fever because your body is fighting off a bad bacteria
The name for the process that causes fertile land to become dirt-like is??
Deforestation
Urbanization
Construction
Desertification
Answer:
Desertification?
Explanation:
Desertification is when fertile lands become desert like
which substance has a mass is 13.5 grams, and its volume is 5 cm 3.
Answer:
Substance is Aluminium
Explanation:
We are given;
Mass; m = 13.5 grams
Volume; V = 5 cm³
Formula for density is;
density = m/V
Density = 13.5/5
Density = 2.7 g/cm³
From the table attached, we can see that the element with a corresponding density of 2.7 is Aluminium
Lead, gold mercury, aluminum which one has the lowest heat capacity?
A reaction yield 6.26 g of a product what is the percent yield if the theoretical yield is 18.81 g
Explanation:
remember the equation percentage yield = actual/theoretical yield
so 6.26/18.81 X 100 gives u 33.28017012 so to 3 SF ot would be 33.3%
hope this helps:)
The statement, that describes the percent yield is 33.280 g.
What is percent yield?The percent yield is the ratio of actual yield to theoretical yield. It is computed by dividing the experimental yield by the theoretical yield and multiplying the result by 100 percent. If the actual and theoretical yields are equal, the percent yield is one hundred percent.
To express the efficiency of a reaction, use the following formula: percent yield
= (actual yield/theoretical yield) x 100
= (6.26 g/ 18.81 g) x 100
= 33.280 g
Hence the correct answer is 33.280 g.
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Help i’m taking a test!!
What new element is formed from the equation below? (Answer form is
MN:, AN: , S)
Answer:
Element Z
Explanation:
I hope this is correct and helps you!
Which of the following is an example of a molecular element?
a.NaCl b. CO2 c. Na d. O2
Answer:
oxygen (O2) is a molecular element
Explanation:
Molecular compound are chemical compounds that take the form of discrete molecules.
atomic element is an element which occurs independently as atoms and can react with other elements to form a compound
Ionic compounds are the compound which on dissolution form ions in solution
Mixture is the composition of different compounds
Mr. Ragusa is approached in his lab by one of his students named Hassan. Hassan had found a bottle of nitric acid that did not have a labeled molarity and wanted Mr. Ragusa to help him find it's molarity. Mr. Ragusa filled a buret to 4.85 mL with 0.30 M NaOH. Mr. Ragusa added 5 mL of the acid to a flask and added some phenolphthalein. Mr. Ragusa hit the titration spot on, and the final volume in the buret was 43.69 mL. What is the concentration of the Nitric Acid?
Round your answer to 2 decimal places. Include a unit in your answer. (ex: 1.2M)
HNO3 + NaOH --> NaNO3 + H2O
Answer:
2.33M
Explanation:
1. First, make sure the equation is balanced. In this case it would be HNO3+NaOH --> NaNO3 + H2O. (it is already balanced here.)
2. Find the initial volume, final volume, the volume of acid, volume of NaOH.
a. Initial Volume: 4.85 mL
b. Final Volume: 43.69
c. Acid (HNO3) Volume: 5 mL
d Volume NaOH: Initial V - Final V --> 43.69 mL - 4.85 mL = 38.84 mL NaOH
3. Find moles of NaOH reacted using the volume from D. Convert this volume into Liters. Multiply the volume of NaOH by molarity of NaOH given to you before. (.30 M NaOH)
a. x mol NaOH/ .03884 L = .30 mol NaOH/ 1 mol = .011652 mol NaOH
4. Now find the moles of acid. The acid given to you in the equation is HNO3. The .011652 mol NaOH is from the moles reacted that you just found. The moles on the right side would be the co-efficient in front of the elements in the equation. Since this equation does not have any coefficients (it's already balanced), it would just be 1.
a. .011652 mol NaOH/ x mol HNO3 = 1 mol NaOH/ 1 mol HNO3.
x = .011652 mol HNO3
5. Now find the concentration, also known as molarity. Divide the .011652 mol by the volume of acid you have been given (5 mL). Before using 5 mL, divide it by 1000 to get the Liter form.
a. .011652 mol HNO3/ .005 L = 2.3304 M HNO3
I hope you understand now. God bless!
How many moles are in a solution with a concentration of 5 M and a volume of 0.25 L?
Answer:
160 mL
Explanation:
If the graph of y = a x 2 + b x + c does not intersect the x -axis, then what is true about the roots? Both are real roots. Both are real roots. Both are imaginary roots. Both are imaginary roots. One is a real root, and one is irrational. One is a real root, and one is irrational. One is a real root, and one is rational.
Answer:
Both roots are imaginary roots.
Explanation:
Consider these things:
If we try to solve x²+1 = 0, notice that we aren't able to solve the equation in Real Number system because there are no negative outputs for quadratic function.
Remember that quadratic function has range greater or equal to the max-min value.
x-axis plane represents the solutions of that equation. If a graph intersects x-axis plane then it has a solution.
While a graph that doesn't have any intersects on x-plane, it means that the equation for that graph doesn't have real solutions but imaginary solutions.
As you may notice some of parabola graph has one intersect, two intersects or none. One intersect is one solution to the equation — Two intersects are two solutions of the equation and lastly, no intersects mean that no real solutions and remain only imaginary solution.
What is the acceleration of a 7 kg
mass being pulled by a 56 N force?
Answer:
8 meters per second per second
Explanation:
Newton's second law: [tex]f=ma[/tex], force = mass multiplied by acceleration.
Therefore 56 / 7 = acceleration = 8
Neptune _____.
is a terrestrial planet
has a nearly horizontal axis
was discovered by mathematical calculations
is the largest planet in the solar system
Answer:
C. Was Discovered by Mathematical calculations
Explanation:
Terrestrial Planets are Inner Planets (Mercury,Venus,Earth,Mars) and Neptune is an ice giant or gas giant, Neptune is also not the largest planet in the solar system, I believe that's Jupiter. I don't know for sure if Neptune has a horizontal axis but my best guess is C. I hope this helps! :^)
Given that ammonia (NH3) acts as a weak base in water with a Kb of 1.8 x 10-5 at 298.0 K, calculate the pH at 298.0 K of a solution prepared by mixing 100.0 mL of a 0.050 M aqueous solution of ammonia with 20.0 mL of a 1.00 M aqueous solution of nitric acid. The final volume of the solution is 120.0 mL.
Answer:
pH = 0.903.
Explanation:
Hello there!
In this case, according to the given information about the problem, we can notice there is a reaction between nitric acid and ammonia, whereas just the H ions from the former are relevant:
[tex]NH_3(aq)+H^+(aq)\rightleftharpoons NH_4^+(aq)[/tex]
Thus, we first calculate the consumed moles of ammonia, it order to evaluate the moles after the reaction:
[tex]n_{H^+}=0.020L*1.00mol/L=0.020mol\\\\n_{NH_3}=0.100L*0.050mol=0.005mol[/tex]
It means there is a leftover of moles of hydrogen ions of 0.015mol; then, we calculate the molarity of the resulting solution as follows:
[tex][H^+]=\frac{0.015mol}{0.120L}=0.125M[/tex]
Finally, we use the formula for the calculation of the pH to obtain:
[tex]pH=-log(0.125)\\\\pH=0.903[/tex]
Which means this solution is highly acidic.
Regards!
Which characteristics do stable ecosystems tend to have
Answer:
Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. Biotic factors include plants, animals, and other organisms. Abiotic factors include rocks, temperature, and humidity. Every factor in an ecosystem depends on every other factor, either directly or indirectly.