I need help plzzzzzz​

I Need Help Plzzzzzz

Answers

Answer 1
I think 25%?
I hope this helps
Answer 2

Answer:

it is 25%

Explanation:

Answering so you can give the other person brainliest :D have a good day


Related Questions

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 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

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

First, since l = n-1,
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.

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%

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.

What type of reaction is displayed below?
HCI + NAOH → NaCl + H20​

Answers

The swapping term


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

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

76.3 g aka 76 g
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.

Where are new volcanoes in the Hawaiian island chain forming

Answers

the next volcano in the Hawaiian chain should form east or south of the Island of Hawai'i. Abundant evidence indicates that such a new volcano exists at Lö'ihi

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:

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 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

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 % 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%

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

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.

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

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

help please i need this

Answers

Frequency is the correct answer

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

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!!

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.

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:

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

Hydrogen and oxygen 1) far from each other on the periodic table

what grade percentage is developing, proficient, exceeding, and emerging?​

Answers

Answer:

Grade A is the best percentage that is developing, proficient, exceeding, and emerging

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:

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.

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

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

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:

If 4 moles of sulfur reacts with 9.5 moles of oxygen, how many moles of oxygen would remain after the reaction ?

Answers

4 Na + O₂ = 2 Na₂O

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!
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