Which of the following shows correctly an ion pair and the correct formula for the ionic compound the two ions form?

A) Cu1+, O2–; CuO

B) Cr3+, I–; CrI

C) Sn4+, N3–; Sn4N3

D) Fe3+, O2–; Fe2O3

Answer: Adenine and guanine are the two purines and cytosine, thymine and uracil are the three pyrimidines. The main difference between purines and pyrimidines is that purines contain a sixmembered nitrogencontaining ring fused to an imidazole ring whereas pyrimidines contain only a sixmembered nitrogencontaining ring. They both are types or categories of nitrogen containing bases present in nuclei acids of DNA and RNA.

Purines are 2 Ring or Carbon Ring, Nitrogen containing bases. That consist of these 2 rings next placed next to each other. These examples include - Adenine and Guanine.

Pyrimidines are 1 or single Ring Nitrogen containing structures. There are 3 nitrogenous bases that are categorized as pyrimidines. Cytosine, Thymine, and Uracil.

Answer:

[tex]\frac{214}{83} Bi[/tex]

Explanation:

In beta emission, a neutron is converted into a proton thereby reducing the neutron:proton (N/P) ratio.

When a beta emission occurs, the mass number remains the same while the nuclear charge increases by one unit. The daughter nucleus is found one place to the right of its parent in the periodic table.

Answer:electron

Explanation:

Answer:

To avoid variation due to concentration

Explanation:

Hope this helps :)

Answer:

I think the answer is letter C

Answer:

Explanation:b

Look at my screenshot:

Answer:

Explanation:

2.2 g/mL is the answer.

Answer:

Yes the given equation is balanced.

Explanation:

Chemical equation:

Fe + O₂       →     Fe₂O₃

Balanced chemical equation:

4Fe + 3O₂       →     2Fe₂O₃

There are four iron and six oxygen atoms on both side of equation thus the given equation is balanced.

The given reaction also follow the law of conservation of mass.

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

This reaction is synthesis reaction:

Synthesis reaction:

It is the reaction in which two or more simple substance react to give one or more complex product.

A + B      →   AB

Answer:

A. The seeds on the ground are going to grow into new trees.

Explanation:

Trees are renewable resources.

Answer:

need points

Explanation:

Answer:

Mass percentage does not have any unit as numerator and denominator contains the same unit. The percent by mass of Ca in CaCl[tex]_2[/tex] is equal to (40/111) x 100. The correct option is option A.

Mass percentage represents the the percentage of each element that is making a particular compound.

Mathematically,

Percentage of mass = (component’s mass ÷ total mass) x 100%

Atomic weight of different element of calcium chloride{ CaCl[tex]_2[/tex]} are

Ca = 40 ; Cl = 35

Total mass of Calcium element in calcium chloride = 40g/mol

Total mass of Chlorine atom in calcium chloride = 35× 2= 71g/mol

Total molar mass of calcium phosphate = 40 +71= 111g/mole

Percentage of calcium in calcium chloride =40÷111 = 36%

Therefore, the percent by mass of Ca in CaCl2 is equal to (40/111) x 100. The correct option is option A.

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Nucleus is present at the centre of atom. It contains protons and neutrons. It is very small as compared to the atom.

Answer:

It is a part of a cell which controls all the activities in the cells and contains the genetic information of the cell that is to be passed down to the next cell when it reproduces.

Explanation:

It is a part of a cell which controls all the activities in the cells and contains the genetic information of the cell that is to be passed down to the next cell when it reproduces.  

Answer:

B. Influenza affects one system, but multiple systems must interact in order to restore homeostasis.

Explanation:

According to the CDC, influenza is a respiratory illness caused by the flu virus of which some symptoms include cough, sore throat, muscle aches, and vomiting.

The statement that represents a reasonable claim about the effects of the flu virus on the body’s ability to maintain homeostasis is that it affects one system which is the RESPIRATORY SYSTEM but multiple systems must intervene in other to maintain homeostatis.

*Homeostatis is the unique way a human body or organism stabilises its internal state despite the changes on the external.

Answer:

A 7.59 mol Ne

Explanation:

The number of moles of Ne in a sample of 4.57 x 10²⁴ atoms of neon (Ne) are 7.59 mol of Ne. Hence Option (A) is the correct option. It can be solved with the help of Mole concept.

The mole, symbol mol, is the SI base unit of amount of substance.

The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample.

n = given number / Avogadro's number

  = 4.57 x 10²⁴ / 6.022 x 10²³

  = 7.59 mol of Ne

Therefore, The number of moles of Ne in a sample of 4.57 x 10²⁴ atoms of neon (Ne) are 7.59 mol of Ne. Hence Option (A) is the correct option. It can be solved with the help of Mole concept.

Learn more about Mole here ;

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Answer:

Arthropod (3)

Annelids (2)

Cnidarians (1)

Echinoderms (4)

Explanations:

I hope all this helps if u don't understand it let me know.

your answer is correct good luckk!!!:)

Answer:

8

Explanation:

u can find it on ur chemistry book

Answer:

C. 8

Explanation:

Check chemistry textbook

Answer:

Ke1/2mv2

Explanation:

Hope this helps

Answer:

KE 1/2 MV2

ExplanationExplanationExplanationExplanation: hope this helps

Answer:

6.591

Explanation:

= 6.951 moles

Answer: 8

Explanation:

Answer:

A

Explanation:

Answer:

B) Na3BO3.

Explanation:

Hello!

In this case, since percent compositions are used to identify the empirical formula of an unknown compound, we can assume we have 54.0 g of sodium, 8.50 g of boron and 37.5 g of oxygen, and we compute the moles of each one:

[tex]n_{Na}=54.0g*\frac{1mol}{23g} =2.35mol\\\\n_B=8.50g*\frac{1mol}{11g}=0.773mol\\\\n_O=37.5g*\frac{1mol}{16g}=2.34mol[/tex]

Now, we divide by the moles of boron as those are the fewest:

[tex]Na:\frac{2.35}{0.773}=3\\\\B:\frac{0.773}{0.773}=1\\\\O=\frac{2.34}{0.773}=3[/tex]

Thus, the empirical formula is B) Na3BO3.

Best regards!

Answer:

1. Alkali metals (group 1)

2. halogens (Group 17)

3. noble gasses (group 18)

Explanation:

1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.

2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.

3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)

I hope this helps.  Let me know if anything is unclear.

Answer:

the change in internal energy of the gases is  -3.0924 KJ

Explanation:

The computation of the change in internal energy of the gases is as follows;

Given that

Q = -3.1 KJ

= -3100 J

It is negative as the heat is lost from the mixture

And,

W = + 7.6 J

It is positive as the work is done in the mixture

Now we use the following equation

Delat E = Q + W

= -3100 J + 7.6 J

= -3092.4 J

= -3.0924 KJ

Hence, the change in internal energy of the gases is  -3.0924 KJ

Answer:

joe.......

Explanation:

mama......

Answer:

Q = 802.6 J

Explanation:

Given data:

Specific heat capacity of water = 4.18 J/g.°C

Mass of water = 12 g

Initial temperature = 23°C

Final temperature = 39°C

Heat required = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 39°C - 23°C

ΔT = 16 °C

Q = 12 g× 4.18 J/g.°C × 16 °C

Q = 802.6 J

Answer:

hi buddy!! here is ur ans: carbon atoms

The answer would be metals :)