Scientists have been classifying living organisms for centuries. In the 1970s, organisms were classified in a five-kingdom
classification scheme. However, two decades later, organisms called Archaebacteria were discovered. This led to a three-domain
system of classification that combined some of the previous five-kingdom schemes.
What does this change in classification methods demonstrate?

Answer:

I believe it is 5.00

Explanation:

Answer:

HPRT

Explanation:

HPRT catalyzes the salvage reactions of hypoxanthine and guanine with PRPP to form IMP and GMP

The formation of GMP from IMP requires oxidation at C-2 of the purine ring, followed by a glutamine-dependent amidotransferase reaction that replaces the oxygen on C-2 with an amino group to yield 2-amino,6-oxy purine nucleoside monophosphate, or as this compound is commonly known, guanosine monophosphate.

Answer:

the mole ratio of chromium to nickel atoms in the steel is 2.383

Explanation:

Given the data in the question;

Chromium  = 19% ( by mass )

Nickel = 9% ( by mass )

now, let the mass of the steel = 100 g

so mass of Chromium  = 19g

mass of nickel = 9g

We know that; Atomic mass of Cr is 52 g/mol, Atomic mass of Ni is 58.7 g/mol

Moles of Cr =  mass/atomic number = 19/52 mol

Moles of Ni =  mass/atomic number = 9/58.7 mol

The mole ratio of of Cr to Ni atom  will be;

⇒ Moles of Cr / Moles of Ni

= (19/52) / (9/58.7)

= 19×58.7 / 9×52

= 2.383

Therefore, the mole ratio of chromium to nickel atoms in the steel is 2.383

Answer:

d

Explanation:

Answer:

hopen it helps soo much thanks for the points

Answer:

3.5 mol

Explanation:

Step 1: Given data

Moles of HCl: 7.0 mol

Step 2: Write the balanced equation

Fe(s) + 2 HCl(aq) ⇒ FeCl₂(aq) + H₂(g)

Step 3: Calculate the moles of H₂ gas produced from 7.0 moles of HCl

According to the balanced equation, the molar ratio of HCl to H₂ is 2:1.

7.0 mol HCl × 1 mol H₂/2 mol HCl = 3.5 mol H₂

Answer:

A 70%

B 92%

C 87%

D 79%

Explanation:

This excercise is about dividing water by liquid.

Answer:

ch4+h2o----725°-->co+2h2

Answer:

your finger becomes negatively charged

Explanation:

hope it helps. follow me

Answer:

Longer bonds have lower attractive force

Answer:

X axis shows the independent and Y axis shows the dependent.

Explanation:

Answer:

B and D

Explanation:

Because its adaptions they need to survive in the cold.

Answer:

a

Explanation:

Answer:

The deviation in the results will be too large when compared with the actual result

Explanation:

The effect this will have on the results of the samples run using this Calibration solution is that the deviation in the results will be too large when compared with the actual result that was supposed to be obtained. and this will also lead to wrong analysis by the technician .

This will cause a result that is very different from the actual result, which will lead to errors in the analysis.

We can arrive at this answer because:

As we can see from the question above, the lab technician used a much higher calibration than what was recommended in the lab. This will lead to inaccurate and incorrect results.

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Answer:

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Explanation:

Aluminum sulfate Al₂(SO₄)₃ has a molar mass of 342.15 g/mol.

Molar mass is the amount of mass that a substance contains in one mole of a substance, which can be an element or a compound.

So in this case you can apply the following rule of three: if 342.15 grams are present in 1 mole of aluminum sulfate, how much mass is present in 0.063*10⁻⁴ moles of the compound?

[tex]mass of aluminum sulphate=\frac{0.063*10^{-4}moles*342.15 grams }{1 mole}[/tex]

mass of aluminum sulphate= 2.15*10⁻³ grams

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Answer: A person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and values of societies.

Explanation: I HOPE THIS HELPS U AND ANSWERS UR QUESTION!!! Stay safe and healthy!

Answer:

176 grams of sugar

explanation is down

Explanation:

250 / 22 = 2000 / x250 ml to 22 grams = 2000 ml to x grams

cross multiply

(250)(x) = (2000)(22)

250x = 44,000

x = 44,000/250

x = 176 grams of sugar 

Answer:

a. pH = 7.0

b. pH = 12.52

c. pH = 12.70

d. pH = 12.78

Explanation:

a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)

pH = -log[H⁺] = 7

b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]

-Total volume = 10mL+5mL = 15mL = 0.015L

pOH = -log[OH⁻] = 1.48

pH = 14-pOH

pH = 12.52

c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]

-Total volume = 10mL+10mL = 20mL = 0.020L

pOH = -log[OH⁻] = 1.30

pH = 14-pOH

pH = 12.70

d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]

-Total volume = 10mL+15mL = 25mL = 0.025L

pOH = -log[OH⁻] = 1.22

pH = 14-pOH

pH = 12.78

Answer:

D. A pond freezing over is not a chemical reaction, it is a physical reaction.

Answer:

A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid.

Explanation:

A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid. The net charge on a zwitterion is zero since it has equal number of positive and negative charges.

Alanine, is a monoamino monocarboxylica acid that is diprotic when fully protonated. The carboxylic acid group, COOH and the amino group, NH₃⁺, are able to produce one proton each. At a pH equal to the isoelectric point of alanine, it exists mainly in the zwitterionic form with the α-amino group protonated as NH₃⁺ and the α-carboxyl group deprotonated as COO⁻ . This is because at the isoelectric point of alanine (6.0), pI is greater than the acid dissociation constant, pKa of the α-carboxyl group whereas, pI is less than the acid dissociation constant, pKa of the α-amino group, so the two groups are negatively and positively charged respectively.

Answer:

A

I honestly think it's A, but I could be wrong. It might be B, but I don't think so.

Answer:

NaNH₂₀

Explanation:

0.5 mol Na, 0.5 mol N, and 10 mol H

To obtain the empirical formulae, we find the mole ratio between the elements and this is done by dividing all through by the smallest mol (0.5)

Na = 0.5 / 0.5 = 1

N = 0.5 / 0.5 = 1

H = 10 / 0.5 = 20

The mole ratio is used to write the empirical formulae. It is given as;

NaNH₂₀

Answer:

77.81 g of CuNO₃

Explanation:

6 CuNO₃  +  Al₂(SO₄)₃  ⇒  3 Cu₂SO₄  +  2 Al(NO₃)₃

This is your chemical equation.  We will need this information for converting from Al(NO₃)₃ to CuNO₃.

First, convert grams of Al(NO₃)₃ into moles using the molar mass.

[tex]44.0g*\frac{mol}{213.01g} = 0.2065mol[/tex]

Next, convert moles of Al(NO₃)₃ to moles of CuNO₃.  You can do this by using the stoichiometry (the numbers in front of the compounds).  For every 6 moles of CuNO₃, you will get 2 moles of Al(NO₃)₃, causing the ratio of CuNO₃ to Al(NO₃)₃ to be 6:2.

[tex]0.2065mol*\frac{6}{2} =0.6197mol[/tex]

Now that you moles of CuNO₃, convert this to grams using its molar mass.

[tex]0.6197 mol * \frac{125.56g}{mol} =77.81 g[/tex]

You will need 77.81 grams of CuNO₃ to produce 44.0 grams of Al(NO₃)₃.

Answer:

0.51 cal/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the temperature change

ΔT = 12.7 °C - 10.4 °C = 2.3 °C

Step 3: Calculate the specific heat of the liquid (c)

We will use the following expression.

c = Q / m × ΔT

c = 14 cal / 12 g × 2.3 °C = 0.51 cal/g.°C

Answer:

[tex]n=0.00259 mol[/tex]

Explanation:

Hello there!

In this case, since the Faraday's constant is 96500 Coulombs per mole, we can set up the following process to obtain the moles in 250 Coulombs:

[tex]n=\frac{250C}{96500C/mol}\\\\n=0.00259 mol[/tex]

Best regards!

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ atoms are in  90.43 mole of copper.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles of copper=90.43 moles

Substituting all the given values in the above equation, we get

number of atoms/molecules= 90.43 × 6.022×10²³

number of atoms/molecules=8.12×10²³ molecules

Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.

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Answer:

the scientific name is Angiosperms

Explanation:

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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!