How many meters are in 21.5 km?

Answer:

Since hydrogen is the first element, its electron configuration is 1s1.

Explanation:

It has only one electron in its valence shell.

Valence electrons are the outermost electrons or electrons in the largest energy level. Hydrogen has only one electron, so that electron is a valence electron.

Answer:

One valence electron !!

Explanation:

Answer:

4.54 * 10^-14 m

Explanation:

From Heisenberg's uncertainty principle, we can write;

Δp.Δx ≥ h/4π

Given that;

Δp =Δmv

So;

Δmv.Δx ≥h/4π

Δmv =2/100(3.5×10^7 m/s * 1.66 * 10^-27)

Δmv =1.162 * 10^-21 Kgms-1

Δx ≥6.63 * 10^-34 /4 * 3.142 * 1.162 * 10^-21

Δx ≥4.54 * 10^-14 m

Answer:

[tex]\boxed {\boxed {\sf About \ 2.96 \ moles \ of \ Argon}}[/tex]

Explanation:

To convert from grams to moles we must use the molar mass, which is found on the Periodic Table.

Use the molar mass as a ratio.

[tex]\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]

Multiply by the given number of grams: 118

[tex]118 \ g \ Ar *\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]

Flip the fraction so the grams of argon will cancel each other out.

[tex]118 \ g\ Ar * \frac{1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]

[tex]118 * \frac{ 1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]

[tex]\frac {118 \ mol \ Ar }{ 39.9 }[/tex]

[tex]2.95739348 \ mol \ Ar[/tex]

The original measurement of grams had 3 significant figures, so our answer must have 3 sig figs.

For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 5 to a 6.

[tex]2.96 \ mol \ Ar[/tex]

There are about 2.96 moles of Argon in 118 grams.

External fertilization in animals usually occurs in water or in damp areas in a process called spawning.

Answer:

A

Explanation:

I believe the Correct answer would be A

Answer:

what i need more details

Explanation:

Answer:

Ionic

Explanation:

AgNO3 is also highly soluble in water. Ionic means that the compound is composed of ions.

Explanation:

Mg + 2HNO2 → Mg(NO2)2 + H2

Answer:

Mg + 2HNO2 → Mg(NO2)2 + H2

Explanation:

Explanation:

20g of Na and 10g of Cl2 which is in excess?

The equation of the reaction is given as;

2 Na + Cl2  --> 2 NaCl

From the equation;

2 mol of Na reacts with 1 mol of Cl2

Converting the masses of reactants given to mol

Number of moles = Mass / Molar mass

Na;

Number of moles = 20 / 23 = 0.8696 mol

Cl2;

Number of moles = 10 / 71 = 0.1408 mol

In the chemical equation, the ratio was 2: 1 however with the masses, we can tell that Na is in by far excess.

0.8696 mol of Na would require 0.4348 of Cl2 (Present = 0.1408 mol)

This means;

Na - Excess Reactant

Cl2 - Limiting Reactant

Second part; How much NaCl would be produced?

The limiting reactant determines how much of the product is formed.

From the equation of the reactant;

1 mol of Cl2 produces 2 mol of NaCl

0.1408 mol of Cl2 would require x mol of NaCl

1  = 2

0.1408 = x

x = 0.2816 mol of NaCl

Converting to mass;

Mass = Molar Mass * Number of moles

Mass = 58.44 g/mol * 0.2816 mol

Mass = 16.46 g

Answer:

248.548

Explanation:

Answer:

the average kinetic energy of its particles increases. When the average kinetic energy of its particles increases, the object's thermal energy increases. Therefore, the thermal energy of an object increases as its temperature increases.

Answer:

A. Na

Explanation:

Sodium is a good conductor of electricity and heat because it has only one electron in its valence shell.

i hope this helps :)

Answer:

C.) P

Explanation:

I believe this is correct, lmk if it's not.

Answer: The enthalpy change for this reaction is, -803 kJ

Explanation:

The balanced chemical reaction is,

[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]

The expression for enthalpy change is,

[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]

[tex]\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+(n_{H_2O}\times \Delta H_{H_2O})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{CH_4}\times \Delta H_{CH_4})][/tex]

where,

n = number of moles  

Now put all the given values in this expression, we get

[tex]\Delta H=[(1\times -394)+(2\times -242]-[(2\times 0)+(1\times -75)][/tex]

[tex]\Delta H=-803kJ[/tex]

Therefore, the enthalpy change for combustion of methane is, -803 kJ

Answer:

It increases.

Explanation:

I hope this helps.

Answer:

Increases

Explanation:

Hope this helps :)

Answer:

Land plants are also known as Embryophytes. Embryophytes are complex multicellular eukaryotes with specialized reproductive organs. The name derives from their innovative characteristic of nurturing the young embryo sporophyte during the early stages of its multicellular development within the tissues of the parent gametophyte.

Explanation:

Answer:

there used for mountains , wait I'm just trynna get points ya feel me

Explanation:

Explanation:

Single displacement (replacement) is kind of reaction in which 1 atom of reactants only change in product.

Answer:

tru

Explanation:

Answer:

mole=mass/molarmass

Explanation:

molar mass of h2o=18

Answer:

Light bulb gives light energy which is usefull

Answer:

(c) light energy

Explanation:

As bulb is used for giving light and hence the energy that it gives is light energy.

Answer:

Element      Symbol Mass percent

Carbon          C            93.7088

Hydrogen  H             6.2912

Answer:

it's the third one

Explanation:

matter can't change, but mass can differ

Answer: equal to

Explanation:

Answer:

hshzjndbejkxn. znkskakannamzm msk

Answer:

letter A.

Explanation:

the rate of a chemical reaction can be raised by increasing the surface area of a solid reactant. this is done by cutting the substance into small pieces, or by grinding it into a powder.if the surface area of a reactant is inceased: more particles are exposed to the other reactant.

HOPE IT HELPS(◍•ᴗ•◍)❤

Answer:

Explanation:

The reaction is:

C₃H₈ + 5O₂  →  3CO₂  +  4H₂O

We see, that the equation is ballanced.

As we have data from only one reactant, we assume the other is in excess.

Ratio is 1:4 (stoichiometry). We solve this, by a rule of three:

1 mol of propane can produce 4 moles of water

Then, 4 moles of propane, may produce

( 4 . 4 ) /1 = 16 moles of water can be made.

Remember, we always have to work with the limiting reactant.