Answers
I hope this helps
Answer:
it is 25%
Explanation:
Answering so you can give the other person brainliest :D have a good day
Related Questions
Whoever gets it right gets brainliest!!
Answers
When different atoms join together, they are called a compound. Compounds are made of molecules (so molecules could be an alternate answer, but not all molecules are compounds)
Answer:
it is compound
Explanation:
Two or more elements combined into one substance through a chemical reaction, such as water, form a chemical compound. All compounds are substances, but not all substances are compounds.
An aqueous solution contains
32.7% KCI (weight weight %)
How many grams of KCl are
contained in 100 g of this solution
Molar Mass
KCE: 74.55 g/mol
H20 18.016 g/mol
Answers
Answer:
32.7
Explanation:
I just did it and got it right
HELP I WILL GIVE YOU BRAINLIST!!!
Pick one substance (ex: water and table salt) and compare two of the atoms connected to each other (ex: H and O, Na and Cl) and answer the following questions for each pair:
1)Are they close or far away from each other on the periodic table?
Do they have similar atomic radii?
2)Do they have a large or small difference in ionization energy? What about for electron affinity?
Answers
what energy is walking?
A. light energy
B. sound energy
C. Thermal energy
D. Mechanical energy
E. electrical energy
Answers
Answer:
Mechanical
Explanation:
Mechanical Energy - is moving energy. It is the form that we most see around us. All moving objects produce mechanical energy. The movements within machines is also mechanical energy.
Examples: People, a rolling bicycle, moving gears, and running cars.
HELPPP HURRY FIRST GET BRAINLEST The rusting of steel wool occurs when the iron in the steel wool combines with what substance?
carbon dioxide
hydrogen
nitrogen
oxygen
Answers
Answer:
iron oxide. aka. oxygen
Explanation:
Rust is the result of a chemical reaction between iron and oxygen, otherwise known as iron oxide. Since steel wool -- and steel in general -- is largely made of iron, steel wool is prone to rust if it doesn't have a rustproof coating on it. The actual reaction that creates rust happens when two iron atoms mix with three oxygen atoms in water; the oxygen bonds to the metal, and a new compound is formed.
what is the percentage composition of carbon and hydrogen in ethane(c2h6,molecular mass 30.0)
Answers
Answer
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
Explanation:
2C+3H2-C2H6
nC=12, nH=1, nC2H6=30
2moles of C-1mole of C2H6
3moles of H-1 mole of C2H6
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
We obviously cannot wait for million years to determine the half-life of technetium, or even years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of pulses and a count of pulses minutes later.
Answers
The question is incomplete, the complete question is;
We obviously cannot wait for 4 million years to determine the half-life of technetium, or even 87.7 years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of No pulses and a count of N1 pulses M minutes later.
Answer:
M1/2 = 0.693/k
Explanation:
Given that the initial count rate is No pulses
The count rate after M minutes is N1
Then from;
A = Aoe^-kt
A= N1
Ao=No
I can now write;
N1 = Noe^-kM
The half life is the time taken for the activity of the radioactive nuclide to reach half its initial value. Hence;
N1/No =e^-kM = 1/2
Taking natural logarithm of both sides as shown below;
-kM1/2 = ln(1/2)
M1/2 = - (ln(1/2)/k)
M1/2 = 0.693/k
If I have 2.500 grams of magnesium how many moles of magnesium do I have?
Answers
Answer:
0.1029(rounded to sig figs)
Explanation:
convert from grams to moles
Amount in grams/molar mass of substance
Molar mass of Mg=24.305
So, 2.500/24.305=0.1028594939
Rounded to 0.1029
What % of original U238 remains after three half lives?
1-50
2-25
3-12.5
4-6.25
Answers
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 best describes the process that occurs when liquid water becomes
ice?
Answers
Answer:
Freezing
Explanation:
When a liquid goes to a solid, this process is called freezing.
Answer:
The water molecules get condensed and form a solid matter called ice. This process is called Condensation.
A chemist needs to know the mass of a sample of to significant digits. He puts the sample on a digital scale. This is what the scale shows:
0
0
0
7
6
.
3
g
If this measurement is precise enough for the chemist, round it to significant digits.
Otherwise, press the "No solution" button.
Answers
In type of scientific measurement, the precision of the measurement is expressed in the significant digits of that measurement. It also used to express measurement to the required degree of accuracy.
Significant digits include every digit except the leading zero(s).
And if the number after the required significant digits is not up to 5, it is rounded down and the required significant digits is written as is. If the number after the required significant digits is at least 5, it is rounded up, and the last number on the significant digits requirement is increased by a factor of 1.
What is the product of the equation shown?
2 Na + S203
A. Na S203
B. NaS40
C. Na2S205
D. Na2S2O3
Answers
Answer:
D
Explanation:
balancing of chemical equations
The concentration of a benzene solution prepared by mixing 12.0 g
C6H6 with 38.0 g CCl4 is __________ molal
Answers
Answer: The concentration of a benzene solution is 4.05 molal
Explanation:
Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.
[tex]Molality=\frac{n\times 1000}{W_s}[/tex]
where,
n = moles of solute
[tex]W_s[/tex] = weight of solvent in g
moles of [tex]C_6H_6[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{12.0g}{78g/mol}=0.154mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]molality=\frac{0.154\times 1000}{38.0g}=4.05[/tex]
Therefore, the concentration of a benzene solution is 4.05 molal
Definition: This is a net gain or loss of electrons.
Example: Your hair gains one when you pull a wool sweater over your head.
res)
Term:
Answers
Answer:
Elecric charge/ Electricity
Explanation:
Electric charge is the net gain or loss of electrons
I hope im right!!
15POINTS I NEED HELP WITH THIS QUESTION PLEASE!
Answers
Answer:
12.76 g
Explanation:
Step 1: Write the balanced equation
4 Fes + 7 O₂ ⇒ 2 Fe₂O₃ + 4 SO₂
Step 2: Calculate the moles corresponding to 11.15 g of O₂
The molar mass of O₂ is 32.00 g/mol.
11.15 g × 1 mol/32.00 g = 0.3484 mol
Step 3: Calculate the moles of SO₂ produced from 0.3484 moles of O₂
The molar ratio of O₂ to SO₂ is 7:4.
0.3484 mol O₂ × 4 mol SO₂/7 mol O₂ = 0.1991 mol SO₂
Step 4: Calculate the mass corresponding to 0.1991 moles of SO₂
The molar mass of SO₂ is 64.07 g/mol.
0.1991 mol × 64.07 g/mol = 12.76 g
help please will give brainly if right
Answers
Answer:
B and D
Explanation:
Because its adaptions they need to survive in the cold.
help please i need this
Answers
A group of students is setting up a test to see whether earthworms, like those shown in the photo, prefer rough or smooth surfaces
Answers
Answer:
they like smooth
Explanation:
How many moles are in 2.5L of 1.75 M Na2CO3
Answers
Answer:
4.375 moles Na2CO3
Explanation:
Formula for molarity is;
M = n/V
Where;
M is molarity
n is number of moles
V is volume
Making n the subject we have;
n = VM
We are given;
M = 1.75 M
V = 2.5 L
Thus;
n = 2.5 × 1.75
n = 4.375 moles Na2CO3
Answer:
4.375 moles Na2CO3
Explanation:
Have a great day
Where are new volcanoes in the Hawaiian island chain forming
Answers
Answer:
The Hawaiian Islands are a very small section of a huge chain of volcanic islands that crosses the northern half of the Pacific Ocean, called the Hawaiian-Emperor Volcanic Island Chain, which is over 6,000 kilometres long. The chain is linear, with a large bend in the middle: the southern half is called the Hawaiian Ridge and the northern half is called the Imperial Seamount.
Explanation:
What type of reaction is displayed below?
HCI + NAOH → NaCl + H20
Answers
Hehe
Answer:
neutralization reaction
Explanation:
This reaction involve an acid (HCl) reacting with a base (NaOH), producing a salt (NaCl) and water. Therefore it's a neutralization reaction
How many molecules are in 13.2 L F2
Answers
Answer:
3.55 x 10^23 molecules F2
Explanation:
molecules = moles x avogadro number
1 mole of gas occupies 22.4 L
moles of F2 = 13.2/22.4= 0.589 moles
moles F2 = 0.589 x 6.022 x 10^23 = 3.55 x 10^23 molecules F2
Hydrogen has an oxidation number of +1 in all compounds excepts when it binds with metals and has an oxidation state of -1.
Answers
Answer:
See explanation
Explanation:
In the periodic table, hydrogen is placed in group 1 for convenience. Hydrogen is not a metal, however, its common oxidation state is +1. It easily forms a univalent positive ion just like group 1 elements.
So, when hydrogen is combined with strongly electropositive metals such as sodium, lithium, etc, hydrogen accepts one electron and exhibits an oxidation state of -1 in those compounds.
Such compounds in which hydrogen is combined with strongly electropositive metals to give a binary compound is called a hydride.
If 4 moles of sulfur reacts with 9.5 moles of oxygen, how many moles of oxygen would remain after the reaction ?
Answers
4* 23 g Na --------> 16 g O₂
9.5 g Na ------------> ?
Mass of O₂ = 9.5 * 16 / 4 * 23
Mass = 152 / 92
Mass = 1.6521 g of O₂
Molar mass O₂ = 16.0 g/mol
1 mole O₂ ------------ 16.0 g
? mole O₂ ------------ 1.6521 g
mole O₂ = 1.6521 * 1 / 16.0
≈ 0.10325 moles of O₂
hope that helped!
Which one of the following represents an acceptable set of quantum numbers for an electron in an atom? (arranged as n, l, ml, and ms)
2, 2, -1, -1/2
3, 3, 3, 1/2
3, 3, 3, -1/2
5, 4,- 5, 1/2
2, 1, 0, 1/2
Answers
5,4,-5,1/2 and 2,1,0,1/2 are the only answer choices left.
Next, since ml = -l to l,
2,1,0,1/2
is the answer because in 5,4,-5,1/2, the ml value of -5 is not in the range of -4 to 4, as notes by the value 4 for l.
3 Zn + 2 MnF3 ---------> 2 Mn + 3 ZnF2
Using the reaction above, calculate how many grams of manganese (Mn) are produced in this reaction when 8.5 moles of Zinc (Zn) are used as a reactant?
Answers
Answer:I’ll ask my teacher
Explanation:
NEEED HELP NOW
A new drug has been released to the public and is popular among
consumers. It is effective in relieving high blood pressure. However, it has
altered some patients' personalities. Which stage of the engineering process
may address this negative side effect?
A. Evaluating test results
B. Looking for improvements
C. Screening
D. Testing
Answers
Answer: looking for improvements
Explanation:
Answer:
B. Looking for improvements
Explanation:
took the quiz and got in right on a pex
A cook prepares a solution for boiling by adding 12.5 g of NaCl to a pot holding 0.750 L of water. At what temperature should the solution in the pot boil? {Normal boiling point is 100oC and Kb = 0.512 oC kg/mol and density of water is 1 kg/L}
Thanks!!
Answers
Answer:A cook prepare a solution for boiling by adding 12.5g of NaCl to a pot holding 0.750L of water. ... 12.5g of NaCl to a pot holding 0.750L of water. At what temperature should the solution in the not boil? *. 1 ... Which of the following is best suited to be counted by moles a. roses in a store b. books in a library c.
Explanation:
Which statement best describes the energy in the food web? A. The amount of energy available at level B depends on the amount of energy available at level C. B. The amount of energy available at level A depends on the energy provided from an abiotic source. C. The amount of energy available at level C is greater that the amount of energy available ate level A. D. The amount of energy available at level B is transferred to level A
Answers
Answer:
The amount of energy available at level A depend on energy provided from an a biotic source
what grade percentage is developing, proficient, exceeding, and emerging?
Answers
Answer:
Grade A is the best percentage that is developing, proficient, exceeding, and emerging