how many valence electrons are there in a magnesium atom?

Answer:

7 elements

Explanation:

Answer:

There are 7 elements

Explanation:

Answer:

inclined plane, a simple machine consisting of a sloping surface, used for raising heavy bodies. The force required to move an object up the incline is less than the weight being raised, discounting friction

Explanation:

The steeper the slope, or incline, the more nearly the required force approaches the actual weight. The steeper the slope, or incline, the more nearly the required force approaches the actual weight.

Answer:

Formula Weight of gas sample = 20.1 g/mole => Neon (Ne)

Explanation:

Use Ideal Gas Law formula to determine formula weight and compare to formula weights of answer choices.

PV = nRT = (mass/fwt)RT => fwt = (mass/Volume)RT = Density x R x T

Density = 0.900 grams/L

R = 0.08206 L·atm/mole·K

T = 0.00°C = 273Kfwt = (0.900g/L)(0.08206L·atm/mole·K )(273K)

= 20.1 g/mol => Neon (Ne)

Answer:

C2H4O2

Explanation:

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Answer:

The chemical change in the stomach, known as food digestion,  is from the enzymes in the liver and stomach where they break down food molecules into even smaller molecules in order for them to be digested more easily.

Answer:

1. weak acid

2. weak base

3. weak acid

4. neutral

5. acidic

6. weak base

Explanation:

You can use a pH level scale like the one I attached, to determine each solution.

Answer:

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Explanation:

Answer:

pH = 11,17

Explanation:

[tex][OH^{-} ] = \frac{n_{OH^{-} } }{V} = \frac{2n_{Ca(OH)_{2} } }{V} = 2[ Ca(OH)_{2} ]\\[/tex]

[tex]Ca(OH)_{2}[/tex]    →   [tex]Ca^ {2+}[/tex]        +     [tex]2OH ^ -[/tex]

[tex]7,53.10^-4[/tex]   → [tex]7,53.10^-4[/tex]   →    [tex]1,506^-3[/tex]

pOH = -log [[tex]OH^-[/tex]] = [tex]-log 1,506^{-3}[/tex] ≈ 2,822

pH = 14- pOH = 14-2,822 = 11,178

Answer:

24

Explanation:

2.40*10=24.0

Answer: C , The strength of the intermolecular forces between the particles in the liquids.

Explanation:

Since we have 4 boiling flasks with liquids that are at a temp of 20⁰C and out of them all, flask C the has most amount of vapour Particles inside of it, because of that we can conclude that it has the weakest Intermolecular force out of the rest of the boiling flasks since at a temp of 20⁰C it has the most amount of gas particles compared with the other flasks, and not to forget the data in the graph shows us the formula and boiling point of flask C that contains pentane and from that data given we can tell that since the boiling point of pentane Is low then it has to have a weak intermolecular forces, causing it to have more vapour Particles than other flasks, proving the answer to be C since showing the strength of the attraction will explain everything we need to know about flask C and why does it have more vapour Particles than the other flasks.

Note:

(A) is not the answer since all the liquid particles in each flask are in random constant motion at a temp of 20⁰C so it does not justify why flask C has more vapour Particles.

(B) is not the answer since showing the relative speeds of each vapour Particle will not justify why flask C has the most amount of gas particles with the respect of its temperature.

(D) is not the correct answer since we already have data given in the graph about the boiling point of pentane and it's formula so showing the particulate representation is useless.

The best explanation is the strength of intermolecular force between the particles in a liquid. Thus option C is correct.

Intermolecular force is defined as the attractive and repulsive force that rises between the molecules of a compound. They are electrostatic in nature.

There are basically five type of intermolecular force.

The first three forces are collectively known as Vander wall force.

Thus, the best explanation is the strength of intermolecular force between the particles in a liquid. Thus option C is correct.

To learn more about intermolecular force, refer to the link below:

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Answer: You have to have good mechanics as well as the curve with velocity and speed.

The MLB Pitchers you see can be an example.

Commentators yelling Nasty Curveball, Strikeout!!

Answer:

Na(Sodium) and C(Carbon) only

Answer:

Na, C

Explanation:

1. KCl, or potassium chloride, is a combination of two elements- so it's a chemical compound.

2. Na, or sodium, can be found on the periodic table of elements. Therefore, it is an element.

3. C, or carbon, can also be found on the periodic table of elements. Therefore, it is an element.

4. H20, or water, is a combination of 2 hydrogen atoms that bonded into an oxygen atom. Combination of 2 or more elements is a chemical compound.

Therefore, the answers are Na and C.

Answer:

Aluminum fluoride is an ionic compound. Meaning that the two elements form a ionic bond. In ionic bonding, atoms receive and donate electrons in order to become stable. In this case, aluminum donates its three outer electrons to three fluorine atoms. Aluminum forms a triple positive aluminium ion (Becomes a cation) and fluorine forms three single negative fluoride ions (Becomes a anion).

Answer:

GRAPHENE is a single layer of graphite

Explanation:

each carbon atom bonded to 3 other carbon atoms forming a hexagonal lattice

Answer:

C. it involves the sharing of electrons

Explanation:

A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.

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Answer:

There are 6.022×1023 molecules in a mole. There are 18.01528 grams of water per mole of water. in 1g water

Explanation:

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Answer:

A) 17.5%

B) 1) 2135 kg

2) 375 kg

C) 91.8

Explanation:

Part (A):

1 tonne= 1000 kg= 100%

Aluminium oxide= 825 kg= 82.5%

Iron (lll) oxide= 100 kg= 10%

Sand= 85 kg= 7.5%

That makes total of 100%

So, the percentage of impurities= Iron (lll) oxide + Sand

=> 10 + 7.5= 17.5%

Part (B):

(1) 1 tonne= 427 kg

Multiplying both sides by 5

=> 5 tonne= 427 * 5

=> 5 tonne = 2135 kg

(2) 1 tonne contains 75 kg sand as impurity

=> 1 tonne= 75 kg

Multiplying both sides by 5

=> 5 tonnes = 75 * 5

=> 5 tonnes = 375 kg

Part (C):

If all of the iron oxide was removed, then only aluminium and sand are left.

Aluminium = 825 kg

Sand= 74 kg

Total of them makes it:

=> 825 + 74 = 899

So,

% age of Aluminium= 825/899 * 100

% age of Aluminium= 0.918 * 100%

% age of Aluminium= 91.8%

Answer:

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Explanation:

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Answer:

the proton and the neutron

The particles present in the nucleus of an atom are the proton and the neutron.

Electrons are present outside the nucleus.

Answer:

science of electromagnetic fields

Explanation:

(winks and runs off)

Answer:

Look at the formula.

Explanation:

Carbon: 10

Hydrogen: 14

Nitrogen: 2

10 + 14 + 2 = 26

Organic, its nicotine

Answer:

Pasteurization is a process in which packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life.

Elements in the same period have the same number of electron shells; moving across a period (so progressing from group to group), elements gain electrons and protons and become less metallic. This arrangement reflects the periodic recurrence of similar properties as the atomic number increases.

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Answer:

But when there is too much phosphorus and nitrogen into water systems, it can speed up the process of eutrophication ( increase in the concentration of minerals and nutrients, which enhances the growth of algae, which causes algal blooms). Due to this, dissolved oxygen level is declined as not enough light penetrates in the water body.

Explanation:

Answer:

Chemical formula: HNO₃

Melting point: −42 °C (−44 °F; 231 K)

Molar mass: 63.012 g·mol−1

Solubility in water: Miscible

Explanation:

When Conc HNO3 acid leaks into seawater presumed to be largely consisting of Sodium Chloride and other dissolved salts, I won't consider it as a chemical reaction rather it is a Physical Change. I presume this activity as a mixture when the acid been the solute becomes a contaminants

The number of mole of ammonium ion, NH₄⁺ in the solution is 0.175 mole

We'll begin by calculating the number of mole of NH₄NO₃ in the solution. This can be obtained as follow:

Volume = 125 mL = 125 / 1000 = 0.125 L

Molarity = 1.40 M

Mole = Molarity x Volume

Mole of NH₄NO₃ = 1.40 × 0.125

Finally, we shall determine the number of mole of ammonium ion, NH₄⁺ in the solution. This can be obtained as follow:

NH₄NO₃(aq) —> NH₄⁺(aq) + NO₃¯(aq)

From the balanced equation above,

1 mole of NH₄NO₃ contains 1 mole of NH₄⁺

Therefore,

0.175 mole of NH₄NO₃ will also contain 0.175 mole of NH₄⁺

Thus, the number of mole of ammonium ion, NH₄⁺ in the solution is 0.175 mole

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