Choose a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, just select one of them.
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.
B. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be lower.
C. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be lower
D. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
E. There was no difference in recovered and original mass, so there is no difference to account for.

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.

Answer:

The answer would be work with.

Explanation:

Because, if we know what the word interact means then we can look for a word similar to interact. hope this makes sense <3.

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

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.

Answer: looking for improvements

Explanation:

Answer:

B. Looking for improvements

Explanation:

took the quiz and got in right on a pex

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%

Answer:

B and D

Explanation:

Because its adaptions they need to survive in the cold.

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:

Answer:

2) A catalyst is not consumed in the course of a reaction.

Explanation:

A catalyst is a substance which increases the rate of  chemical reaction and remains chemically unchanged at the end of the reaction.  The addition of a catalyst increases the rate of both reversible and irreversible reactions. including reversible reactions involving a final equilibrium state. In reversible reactions, catalysts speed up the time for equilibrium to be attained.

Considering the given statements about catalysts:

1) In an equilibrium process, a catalyst increases the rate of the forward reaction, but leaves the rate of the reverse reaction unchanged.

False: A catalyst increases both the forward and reverse reaction rates equally, thereby allowing the system to reach equilibrium faster.

2) A catalyst is not consumed in the course of a reaction.

True: Catalysts are substances that increase reaction rates without being consumed in the reaction.

3) A catalyst must be carefully chosen to shift the equilibrium toward products.

False: A catalyst does not affect the extent or position equilibrium of a reaction since a catalyst speeds up both the forward and back reactions by  equal amounts , rather it helps a reaction achieve equilibrium faster.

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.

Answer:

32.7

Explanation:

I just did it and got it right

Answer:I’ll ask my teacher

Explanation:

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

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%

Explanation:

if they aren't in a solvent, then you magnetize first, to remove the iron fillings, secondly, you can sieve to separate the sand and pebbles

Separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips.

To separate their soil mixes using the tools you have supplied, ask the groups to develop a plan. They might consider using forceps to separate the soil, shaking it between two tumblers, placing it in a water-filled tumbler, or pouring it through air. Invite student groups to present their ideas.

Pbbles  - Separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips. As a strainer, a colander or a section of window screen works well. Iron fillings Using a magnet, it is simple to remove the tiny iron filings from the mixture.

Therefore, separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips.

To know more about separartion here:

https://brainly.com/question/16774902

#SPJ2

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:

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

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

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

Answer:

D

Explanation:

balancing of chemical equations

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

Answer:

Elecric charge/ Electricity  

Explanation:

Electric charge is the net gain or loss of electrons

I hope im right!!

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.

Answer:

they like smooth

Explanation: