Answer:
12.5
Explanation:
After three half-lives, one eighth (1/2 x 1/2 x 1/2) of the uranium-238 will remain. One-eighth equals 12.5%
Which change represents an oxidation reaction?
PLEASE HELP!!!
a person measures the mass of a 10cm3 rock to be 15g. what is the density of the rock
Answer:
[tex]d=1.5\ g/cm^3[/tex]
Explanation:
Given that,
The mass of the rock, m = 15 g
The volume of the rock, V = 10 cm³
We need to find the density of the rock. The density of an object is equal to the mass per unit volume such that,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{15\ g}{10\ cm^3}\\\\d=1.5\ g/cm^3[/tex]
So, the density of the rock is equal to [tex]1.5\ g/cm^3[/tex].
Assume the copper was not thoroughly dried. How will the following calculations be affected?
The calculated mass of copper will be too low or too high?
The calculated moles of copper will be too low or too high?
The calculated mass of chlorine will be too low or too high?
The calculated moles of chlorine will be too low or too high?
Calculate the percent composition (out of 100) by weight of potassium in potassium carbonate decahydrate.
Answer:
12.26%
Explanation:
MM K = 39.1 g/mol
MM K2CO3 . 10H2O = 2x39.1 + 12.01 + 3 x 15.99 + 10 x 18.02= 318.38 g/mol
% by weight = (MM K/MM K2CO3.10H2O ) x 100= (39.1/318.8) x 100=12.26 %
The percent composition by weight of potassium in potassium carbonate decahydrate is 13.98%
Let's represent the chemical formula of the compound as follows;
potassium carbonate decahydrate = CH₂0KO₁₃
The molecular mass of the compound can be calculated as follows:
Molecular mass of CH₂₀KO₁₃molecular mass = 12 + 20 + 39 + (16×13) = 279 g/molmass of potassium = 39 g
Therefore,
% mass of potassium = 39 / 279 × 100
% mass of potassium = 3900 / 279
% mass of potassium = 13.9784946237
% mass of potassium = 13.98 %
learn more on percentage composition here: https://brainly.com/question/3905173
Which pieces of information do you need to locate a particular star on a star
Answer:
You need a telescope and a pear of eyes
Explanation:
Ok so this is my opinion you will need a telescope and you will also need it to be night and need eyes of course!
Who tryna do these 3 assignments on wizer for me
An example of a suspension is:
A. blood
B. gelatin
C. muddy water
D. milk
hi, if your looking for extra points (50+) and brainiest here is ur chance, answer this question correctly plz
Answer:
Answer choice 'C'
Explanation:
As the ball slows after kicking generates maximum Kinetic Energy, the ball slows due to its Kinetic Energy being transferred to surroundings because of atmospheric and surface friction until it stops in a state of static equilibrium.
Think about a hot summer afternoon at the beach
or a lake. How do the temperatures of the sand
and water compare?
A. The sand is hot; the water is cool.
B. The sand is hot; the water is hot.
C. The sand is cool; the water is cool.
D. The sand is cool; the water is hot.
Answer:
D
Explanation:
I say this because of this that I read. There was a study shown
"Our experiment was a success. We obtained data that answered our problem, “Which substance absorbs the most heat on a hot day? Sand, water, or sand with water?” The results showed that from the twenty-five trials: the cup of sand temperature ranged from 63-68°C, cup of water temperature ranged from 71-77°C, and the cup of sand with water temperature ranged from 66-71°C. Based on our data, our hypothesis was incorrect. We hypothesized that the sand would absorb the most heat since it is darker and less reflective than water; but from our data, water absorbed the most heat. In conclusion, sand absorbed the least amount of heat and water absorbed the most. Next time we want to cool down at the beach, we’ll know where to go!"
This was an experiment that was performed and this is the conclusion
Hope that helps
Which units can be used to measure length or distance? Check all that apply.
gram
meter
kilometer
liter
inch
Answer:
Meter, kilometer & inch - used to measure length or distance.
How many moles of KBr are present in 1000 ml of a 0.02 M KBr solution?
1. .00002
2. 20
3. 50000
4. .02
5. 50
Answer:
4. .02
Explanation:
Hello there!
In this case, since the molarity of a solution is defined as the moles of the solute divided by the volume of the solution, we can see we are given the molarity and volume and are asked to compute moles; thus, we can solve as shown below:
[tex]M=\frac{n}{V}\\\\n=M*V[/tex]
Whereas the volume must be in liters (1 L in this case); in such a way we can plug in the volume and molarity to obtain:
[tex]n=0.02mol/L*1L\\\\n=0.02mol[/tex]
Therefore, the answer is 4. .02 .
Best regards!
Name the functional group in the
following molecule:
HSCH2CH3
A. alkane
B. amide
C. thiol
D. alkyl halide
Answer:
C. thiol
Explanation:
Answer:
it's C thiol I just took the test
hope this helps
have a good day :)
Explanation:
Calculate the molecular mass for the following: SnO2
Answer:
[tex]MM=150.71g/mol[/tex]
Explanation:
Hello there!
In this case, since the molar masses of chemical compounds allow us to understand the mass they have per mole of substance, for tin oxide, we can see it has one tin atom and two oxygen atoms; thus, for the calculation of this molar mass we multiply the atomic masses by the number of atoms and them add the results up:
[tex]MM=m_{Sn}+2m_O\\\\MM=118.71g/mol+2*16.00g/mol\\\\MM=150.71g/mol[/tex]
Best regards!
Sam and Jane have been investigating the amount of copper sulphate that can be dissolved in water at different temperatures .They added copper sulphate till it could not be dissolved any further and also measured the mass of copper. The results are below. What conclusions can you make from results?
Answer:
This question is so confusing, I'm sorry
molar mass of Mg(CO3)
Answer:
[tex]\boxed {\boxed {\sf 84.313 \ g/mol}}[/tex]
Explanation:
The molar mass is the mass per mole of an element or substance. The values for atomic mass on the Periodic Table are used as the molar mass. Look up the molar masses for the elements in the formula.
Mg: 24.305 g/molC: 12.011 g/molO: 15.999 g/molAnalyze the formula. Magnesium and carbon have no subscript, so there is only one atom of each. Oxygen has a subscript of 3, so there are 3 atoms and the mass has to be multiplied by 3.
MgCO₃= 24.305 + 12.011+ 3(15.999) MgCO₃= 24.305+12.011+47.997=84.313 g/molThe molar mass of magnesium carbonate is 84.313 grams per mole.
Pb(NO3)+MgI2=Mg(NO3)+PbI2 what type of reaction?
Pb(NO3) + MgI2 = Mg(NO3) + PbI2 is an example of a double-replacement reaction.
How many moles are 9.9 * 1024 molecules of methane?
A falling ball looses its shape and bounces off the ground because it has...Immersive Reader
Kinetic energy
Potential energy
Elastic energy
Thermal energy
Which unit is NOT correctly paired?
O Liters : Volume
O Formula Mass : Count
O Grams: Mass
O Molecules : Mass
Answer:
Molecules : Mass
Explanation:
The first three answer choices correctly pair a unit with what it measures. Molecules are not used to measure mass; grams are.
What information does the percent composition of an atom in a molecule
give?
Answer:
percent composition tells that by mass
12
"C
What is the number of protons in this carbon atom?
ÖA 12
OB. 6
Ос.
18
OD. 24
what is the answer
Answer:
B
Explanation:
the number of protons never changes even if the atomic mass changes
Instruction
Active
TRY IT Writing Measurements in Scientific Notation
Choose the scientific notation that best represents the standard notation given.
6,840,000,000 m
68.4 x 108 m
6.84 x 108 m
6.84 x 10-9 m
6.84 x 109 m
0.000000000143 g
-1.43 x 1010 g
1.43 x 10-10 g
14.3 x 1010 g
14.3 x 10-10 g
COMPLETE
DONE
Answer:
D & B
Explanation:
just did it
During a hurricane, what effect can the ocean have on the beach?
How many formula units make up 10.2 g of magnesium chloride (MgCl2)?
Answer:
6.46×10²² formula units
Explanation:
From the question given above, the following data were obtained:
Mass of MgCl₂ = 10.2 g
Number of formula units =?
From Avogadro's hypothesis,
1 mole of MgCl₂ = 6.02×10²³ formula units
But,
1 mole of MgCl₂ = 24 + (35.5×2) = 24 + 71 = 95 g
Thus, we can say:
95 g of MgCl₂ = 6.02×10²³ formula units
Finally, we shall determine the formula units in 10.2 g MgCl₂. This can be obtained as follow:
95 g of MgCl₂ = 6.02×10²³ formula units
Therefore,
10.2 g of MgCl₂ = (10.2 × 6.02×10²³) / 95
10.2 g of MgCl₂ = 6.46×10²² formula units
Thus, 10.2 g of MgCl₂ contains 6.46×10²² formula units
HELPPP PLZZ
During lunch each day, Alex and Hailey have been noticing the trashcans around the lunchroom are filling rather quickly with cans and bottles. They decide a recycling program would be beneficial for their school and the environment, so they brainstorm ways to get the program started. Before discussing their idea with the principal, they need to decide which of their plans would best solve the problem. Which of their ideas would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved? A) Ask volunteers to separate recyclable materials from the trash. B) Remove all vending machines that sell plastic bottles or aluminum cans. C) Get a petition started to build a recycling center close to the school. D) Place plastic and metal recycling bins next to each lunchroom trash can
Answer:
c
Explanation:
i think it is C but idek but to me it sounds like the best answers but tell me if im wrong pls give me feedback
The ideas that would best solve the problem with the least amount of inconvenience is to place plastic and metal recycling bins next to each lunchroom trash can.
What is recycling?The term recycling has to do with the reuse of a material after it has passed through certain processes. The idea of recycling is highly beneficial to the environment.
Thus, the ideas that would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved is to place plastic and metal recycling bins next to each lunchroom trash can.
Learn more about recycling:https://brainly.com/question/11861824
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PLEASE HELP ME!!! i have no idea how to answer these!
Answer: Im answering this for points
DONT COME ON MY STUFF SAYING THAT I GOT SCHOOL TO DO JUST LIKE YOU AND YOUR GIVING ME IRRELEVANT ANWSERS JUST TO GET POINTS? THATS A WASTE OF MY TIME
Explanation:
Please someone help me with this!!
2 CH3OH + 3 02 2 CO2 + 4H2O
What is the mass of oxygen (O2) that is required to produce 579 g of carbon dioxide (CO2)?
. Your answer should have three significant figures.
Answer:
632 g
Explanation:
2CH₃OH + 3O₂ → 2CO₂ + 4H₂OFirst we convert 579 g of CO₂ into moles, using its molar mass:
579 g CO₂ ÷ 44 g/mol = 13.16 mol CO₂Then we convert CO₂ moles into O₂ moles, using the stoichiometric coefficients:
13.16 mol CO₂ * [tex]\frac{3molO_2}{2molCO_2}[/tex] = 19.74 mol O₂Finally we convert O₂ moles into grams, using its molar mass:
19.74 mol O₂ * 32 g/mol = 632 gwhat is a 7 letter word that starts with f: Ancient plants and animals formed into rocks.
Answer:
Fossils?
Explanation:
What atom has the largest atomic radius barium calcium magnesium radium
Answer:
Radium
Explanation:
It has the highest atomic number so it would have more shells, making it larger than the others.