If a mineral isn't scratched by a fingernail, what can you conclude about the minerals
hardness?
It is at least a hardness of 4.0
A mineral can't be tested by a fingernail.
The hardness is more than 2.5.
The hardness is less than 2.5.

Answer:

Hazen uses small metal cylinders called pressure bombs to blast minerals with insanely high pressures and temperatures. He's using that knowledge to figure out how ancient minerals might have been involved in the evolution of the first primitive life-forms.

Explanation:

Answer:

Homeostasis is defined as the process by which the internal body system maintains a suitable environment for its proper functions and survival.

When a person temperature drops a signal is sent to the brain which results in a reflex action being observed. The shiver makes the individual warmer and helps in the regulation of the body heat.

Answer: The volume of solution is 0.0459 L

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution

[tex]Molarity=\frac{n}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in L

moles of HCl (solute) = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{2.43g}{36.5g/mol}=0.0666[/tex]

Now put all the given values in the formula of molality, we get

[tex]1.45M=\frac{0.0666}{V_s}[/tex]

[tex]V_s=\frac{0.0666}{1.45}=0.0459[/tex]

Therefore, the volume of solution is 0.0459 L

Answer:

The correct answer is 0.12 grams.

Explanation:

The mass of carbon monoxide or CO collected in the tube can be determined by using the ideal gas equation, that is, PV = nRT.

Based on the given question, P or the pressure of the gas is given as 1 atm, volume of the gas collected in the tube is 117 ml or 0.117 L.  

The number of moles or n can be determined by using the equation, mass/molar mass.  

R is the universal gas constant, whose value is 0.0821 L atmK^-1mol^-1, and temperature is 55 degree C or 328 K (55+273).  

On putting the values we get:

n = PV/RT

= (1 atm*0.117 L) / (0.0821 L atmK^-1mol^-1 * 328 K)

= 0.0043447 mol

Therefore, mass of CO will be moles * molar mass of CO

= 0.0043447 mol * 28 g/mol

= 0.12 g

Answer:

17202.6 years

Explanation:

Activity of the living sample (Ao) = 160 counts per minute

Activity of the wood sample (A) = 20 counts per minute

Half life of carbon-14 = 5730 years

t= age of the artifact

From;

0.693/t1/2= 2.303/t log Ao/A

Then;

0.693/ 5730= 2.303/t log Ao/A

Substituting values;

0.693/5730= 2.303/t log (160/20)

Then we obtain;

1.209×10^-4 = 2.0798/t

t= 2.0798/1.209×10^-4

Thus;

t= 17202.6 years

Therefore the artifact is 17202.6 years old.

Answer:

1.52M in NaCl

Explanation:

Molarity = moles solute / volume solution in Liters

=> molarity (M) = 3.8 moles / 2.5 Liters solution = 1.52 molar solution in NaCl

Answer: 1.52

Explanation:

Answer:

right now we are using energy by online learning on our laptops , air conditioning, and transportation

Explanation:

Answer:

The limiting reagents seemed to be those that were consumed first .

Because when this reagent is consumed, the reaction stops. The quantity of this determines the total quantity of the product formed.

Explanation:

A limiting reagent is one that is consumed in its entirety. In this way, it delimits the amount of product that can be formed.

Take the case of two substances that interact and produce a chemical reaction. If one of the substances runs out as it is consumed during the process, the reaction will stop. The reagent consumed acts as a limiting reagent, that is, it limits the possibility of the reaction proceeding, and therefore it also limits the amount of the product generated by the reaction.

Answer:

Explanation:

The boiling point of water is 100 °C or 212 °F at 1 atmosphere of pressure (sea level).

Answer:

c

Explanation:

Answer:

gas

Explanation:

If you put gas in anything, it will occupy shape and volume.

Liquid only occupies shape of the container, whereas, solid doesn't occupy shape or volume because it maintains a fixed volume and shape.

Answer:

A. Buffer strips

Explanation:

The practice that could help reduce erosion of water banks is buffer strips.

Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.

One of the practices that could be used to reduce the effect of erosion is buffer strips.

What buffer strips do is slow and filter storm runoff while helping to hold soil in place.

Learn more on buffer strips here; https://brainly.com/question/26872640

Answer:

46.07 g/mol is the molar mass of ethonal

Sublevel 2s and 2p contains the valence electrons for nitrogen.

Answer:

i don't understand

Explanation:

There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.

What is periodic table?

Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.

Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.

Periodic table is the best platform to have a look to all elements at once that are arranged in columns and groups mentioning their valencies, electronegativity and Ionisation energy symbols. Thus the option c is correct option.

Learn more about periodic table , here:

https://brainly.com/question/11155928

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Answer:

octet rule

Explanation:

It refers to the tendency of atoms to prefer to have eight electrons in the valence shell.

Answer:

Table salt (the iodine isn't important) consists of much smaller particles than rock salt and therefore has a much higher ratio of surface area to mass. Since chemical reactions occur at surfaces,the smaller table salt particles will dissolve far more quickly than the larger rock salt.

Explanation:

Answer:

Individual salt crystals

Explanation:

A given quantity of solute dissolves faster when it is ground into small particles than if it is in the form of a large chunk because more surface area is exposed.

Give me a good review if right please.

Answer:

120.4 gradius Celcius

Explanation:

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

Answer:

Specific heat

Explanation:

Answer:

Specific Heat

Explanation:

A P E X

Answer:

1.02 g OF CALIFORNIUM-254 WILL REMAIN AFTER 363 DAYS IF 64 g REACTS WITH HALF LIFE OF 60.5 DAYS.

Explanation:

Half life of a chemical reaction is the time required for a radioactive element to decay to half its original mass.

We will use the formula:

                                    Nt = No (1/2)^t/t1/2                                            where;

Nt = quantity of substance remaining = unknown

No = original mass of the substance = 64 g

t = time elapsed = 363 days

t1/2 = half life of the substance = 60.5 days

Putting the values into the equation, we have:

Nt = 64 * (1/2)^(363/60.5)

Nt = 64 * (1/2) ^6

Nt = 64 * 0.015625

Nt = 1.0156

The amount of californium-254 remaining after 363 days is approximately 1.02 g

Answer:

[tex]pOH=1.3[/tex]

Explanation:

Hello,

In this case, since pH is computed by knowing the concentration of hydrogen ions, one could compute the pOH by knowing the concentration of the hydroxyl ions as in this case which is 0.045M as shown below:

[tex]pOH=-log([OH^-])=-log([0.045])\\\\pOH=1.3[/tex]

Best regards.

Answer:

The pOH of the 0.045 M solution is 1.3

The second option (1.3) is correct

Explanation:

Step 1: Data given

Concentration [OH-] of KOH is 0.045 M

Step 2: Calculate pOH

pOH = -log[OH-]

pOH = -log (0.045)

pOH = 1.3

The answer:

The pOH of the 0.045 M solution is 1.3

The second option (1.3) is correct

Answer:

a)

[H₂O] = 0.0455M

[Cl₂O] = 0.0130M

[HOCl] = 0.0200M

b) Kc = 0.676

c) [H₂O] = [Cl₂O] = 0.177M

Explanation:

Based on the reaction:

H₂O(g) + Cl₂O(g) ⇄ 2HOCl(g)

Kc is defined as:

Kc = [HOCl]² / [H₂O][Cl₂O] For molar concentrations in equilibrium

As volume of the flask is 1.00L, the initial molar concentrations of H₂O and Cl₂O is 0.0555M and 0.0230M, respectively.

In equilibrium, the concentrations are:

[H₂O] = 0.0555M - X

[Cl₂O] = 0.0230M - X

[HOCl] = 2x = 0.0200M → X = 0.0100M

Where X is reaction coordinate

a) Concentrations in equilibrium are:

[H₂O] = 0.0455M

[Cl₂O] = 0.0130M

[HOCl] = 0.0200M

b) Replacing in Kc:

Kc = [0.0200]² / [0.0455][0.0130] = 0.676

c) Initial concentration of HOCl is 1.0mol / 2.0L = 0.50M. In equilibrium concentrations are:

[H₂O] = X

[Cl₂O] = X

[HOCl] = 0.50M - 2X

Replacing in Kc formula:

0.676 = [0.50-2X]² / [X][X]

0.676X² = 4X² - 2X + 0.25

0 = 3.324X² - 2X + 0.25

Solving for X:

X = 0.177M

X = 0.425M → False answer, produce negative concentrations.

As X = [H₂O] = [Cl₂O]; equilibrium concentrations of both compounds is 0.177M

Answer:

just did it the answers b

Explanation:

Answer:

Ionic bonds

Explanation:

It rymes.  haha i dont even know how to spell it! ;)

Answer:

.01

Explanation:

H+=10^-pH

- Hope that helps! Please let me know if you need further explanation.

Answer:

2

Explanation:

pH+pOH=14

- Hope that helps! Please let me know if you need further explanation.

Answer:

2

Explanation:

Ph+PoH=14

Answer:

a) 2Al + 3Cl2 ⇆ 2AlCl3

b) Cl2 is the limiting reactant.

c)  2.0 moles AlCl3

d) There will remain  3.2 moles Al

Explanation:

Step 1: Data given

Number of moles Al = 5.3 moles

Number of moles Cl2 = 3.0 moles

Step 2: The balanced equation

2Al + 3Cl2 ⇆ 2AlCl3

Step 3: Calculate the limiting reactant

For 2 moles Al we need 3 moles Cl2 to produce 2 moles AlCl3

Cl2 is the limiting reactant. It will completely be consumed. (3.0 moles)

Al is in excess. There will react 2/3 * 3.0 = 2.0 moles

There will remain 5.2 - 2.0 = 3.2 moles

Step 4: Calculate moles AlCl3

For 2 moles Al we need 3 moles Cl2 to produce 2 moles AlCl3

For 3.0 moles Cl2 we'll have 2/3 * 3.0 = 2.0 moles AlCl3

Answer:

The correct answer to the following question will be "0.0013%".

Explanation:

The given values are:

Weight of an empty dish = 1.0041 ± 0.0002 g

Weight of dish + sodium chloride (NaCl) = 3.2933 ± 0.0002 g

Weight of NaCl = 2.2892 ± 0.0002 g

Now,

Volume of the solution = 500.00 ± 0.05 ± 0.0002

                                      = 500.00 ± 0.0502 ml

So,

Molarity = [tex]\frac{W \ NaCl}{M \ NaCl} \times \frac{1000}{Volumes \ of \ solution}[/tex]

On putting the values in the above formula, we get

             = [tex]\frac{(2.2892\addeq +0.0002)}{58.440}\times \frac{1050}{(500.00+0.0502)}[/tex]

             = ([tex]3.917[/tex] ± [tex]0.0002[/tex]) × ([tex]2[/tex] ± [tex]0.0502[/tex])

             = ([tex]0.7834[/tex] ± [tex].00001004[/tex])

Now,

Absolute error = [tex]\frac{0.00001004}{0.7834}\times 100[/tex]

                         = [tex]0.0013[/tex]%