Are all elements atoms and are all atoms elements?

Answer:

the atomicity of sulphur is 8

Explanation:

hope it helps

Answer:

A. 70 K

B. 3.16 atm

Explanation:

We'll begin by calculating the number of mole in 175 g of Ar. This can be obtained as follow:

Mass of Ar = 175 g

Molar mass of Ar = 40 g/mol

Mole of Ar =?

Mole = mass / molar mass

Mole of Ar = 175 / 40

Mole of Ar = 4.375 moles

A. Determination of the temperature.

Mole of Ar (n) = 4.375 moles

Volume (V) = 2.50 L

Pressure (P) = 10 atm

Gas constant (R) = 0.0821 atm.L/Kmol

Temperature (T) =?

PV = nRT

10 × 2.5 = 4.375 × 0.0821 × T

25 = 4.375 × 0.0821 × T

Divide both side by (4.375 × 0.0821)

T = 25 / (4.375 × 0.0821)

T ≈ 70 K

B. Determination of the pressure.

Mole of Ar (n) = 4.375 moles

Volume (V) = 2.50 L

Temperature (T) = 22 K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure (P) =?

PV = nRT

P × 2.5 = 4.375 × 0.0821 × 22

Divide both side by 2.5

P = (4.375 × 0.0821 × 22) / 2.5

P = 3.16 atm.

Answer:

D

Explanation:

B is solid and liquid while D is liquid and gas

Answer:

Option ( D) is correct

The phase transition occurs at 100o C (the normal boiling point of water). Liquid water becomes water vapor or steam when it enters the gaseous phase.

Explanation:

A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it.

The liquid will begin to boil when enough heat has been absorbed by the solution that the temperature reaches the boiling point, where again, the temperature remains constant until all of the liquid has become gaseous water. At the atmospheric pressure of 1 atm, this phase transition occurs at 100o C (the normal boiling point of water). Liquid water becomes water vapor or steam when it enters the gaseous phase. Use the heat of vaporization ([latex]\Delta H_{vap}[/latex] ) to calculate how much heat was absorbed in this process: [latex]q=m\cdot C_{H_2O(g)}\cdot \Delta T[/latex], where m is the mass of the sample of water.

After all of the liquid has been converted to gas, the temperature will continue to increase as heat as added. Again, the heat added that results in a certain change temperature is given by: [latex]q=m\cdot C_{H_2O(g)}\cdot \Delta T[/latex] . Note that the specific heat capacity of gaseous water is different than that of ice or liquid water.

Answer:

This is because Mendeleev arranged the elements in order of increasing relative atomic mass.

Explanation:

Dmitri Mendeleev is one of the scientists that contributed to the development of periodic table in chemistry. He was able to organise elements into rows according to their atomic mass and into columns based on chemical and physical properties. This is the main reason why his periodic table is still studied even though it has some defects which include:

--> Grouping of elements that are not similar chemically: For example Copper and Silver bear no resemblance with the alkali metals, but they have been placed together in the first group.

--> Position of isotopes: According to his periodic table: Isotopes of an element must be given separate places in the periodic table because they have different atomic masses.

--> Electronic arrangement of elements: It failed to explain the electronic arrangement of elements.

--> Separation of chemically similar elements:

Elements that are chemically similar such as Gold and Platinum have been placed in separate groups.

Answer:

[tex]\boxed {\boxed {\sf 761 \ K}}[/tex]

Explanation:

We are asked to find the new temperature of a gas after a change in volume. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]

The volume is initially 52.3 liters at a temperature of 273 Kelvin.

[tex]\frac {52.3 \ L}{273 \ K}= \frac{V_2}{T_2}[/tex]

The volume reaches 145.7 liters at an unknown temperature.

[tex]\frac {52.3 \ L}{273 \ K}= \frac{145.7 \ L }{T_2}[/tex]

We are solving for the new temperature, so we must isolate the variable T₂.  Cross multiply. Multiply the first numerator and second denominator, then the first denominator and second numerator.

[tex]52.3 \ L * T_2 = 273 \ K * 145.7 \ L[/tex]

Now the variable is being multiplied by 52.3 liters. The inverse of multiplication is division. Divide both sides by 52.3 L.

[tex]\frac {52.3 \ L * T_2 }{52.3 \ L}=\frac{ 273 \ K * 145.7 \ L}{52.3 \ L}[/tex]

[tex]T_2=\frac{ 273 \ K * 145.7 \ L}{52.3 \ L}[/tex]

The units of liters cancel.

[tex]T_2=\frac{ 273 \ K * 145.7 }{52.3 }[/tex]

[tex]T_2 = 760.5372849 \ K[/tex]

The original measurements have at least 3 significant figures, so our answer must have 3. For the number we found, that is the ones place. The 5 in the tenths place tells us to round the 0 up to a 1.

[tex]T_2 \approx 761 \ K[/tex]

When the volume reaches 145.7 liters, the temperature is 761 Kelvin.

Answer:

NAO SRESONDEPORR PQUEOU BUOBRRRA  IGAD THCAAUSEI

Explanation:

Answer:

It's already balanced.

Explanation:

REACTANTS PRODUCTS

H = 2 H =2

S = 1 S = 1

O = 7 O = 7

Ca = 1 Ca = 1

C = 1 C =1

Answer:

see explanation

Explanation:

Solutions are prepared from one of three solute sources ...

- solid solute from manufacturer,

-liquid solute from manufacturer,

-stock concentrate of solute for dilution to lower concentrations.

In this problem, sucrose is a stock solid with a formula mass of 342.3 grams/mol. The amount of solid needed can be determined using the formula:

mass of solute needed (grams) = (Molarity needed x Volume needed in Liters x formula weight) / (decimal fraction purity of stock solid)

Molarity needed = 0.3M

Volume needed = 500 ml = 0.500 liters

Formula weight = 342.3 grams/mole

Purity factor (assumed) = 100% = 1.00 (should be posted on stock bottle label) For example, a 95% pure stock solid => purity factor of 0.95.

∴ grams of sucrose needed = (0.3M*)(0.500L)(342.3g/mole)/(1.00) =51.345 grams sucrose.

Measure 51.345 grams of sucrose into mixing vessel and add solvent water up to, but not to exceed 500 ml total volume. Mix until homogeneous.

Answer:

answer of your question is 4th

Explanation:

P205

Answer:

answer is in the picture.

Answer:

MnO4 + 4 H2C2O4 = Mn + 8 CO2 + 4 H2O

Answer.

Hydrocarbons are compounds that contain carbon and hydrogen only

Explanation:

a. c3H4 methane

b.c3H4.propene

c.c5H8

Answer:

Yes

Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. ... Notable gemstones high in beryllium include beryl (aquamarine, emerald) and chrysoberyl.

Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat. About 99% of the calcium in our bodies is in our bones and teeth.

Answer:

Phosphorus atoms can bond with oxygen atoms to form ester groups. These can bond with carbon atoms, yielding a large number of organic phosphorus chemicals. These are found in many important biological processes

Answer:

C. Enlargement

Explanation:

Answer:

a. B

b. C

c. A

d. A

e. B

f. -266

g. B and D

Answer:

The answer is HSO4- is a weak acid which will be C

The acid dissociation constant, ka, of HSO4- indicates that it is a strong acid. Details about acid dissociation constant can be found below.

The acid dissociation constant denoted by Ka is the measure of the strength of an acid.

The dissociation constant of an acid is used to identify strong acids from their weak counterparts. Strong acids have high Ka values while weak acids have low Ka values.

According to this question, the Ka of HSO4- is 1.2 × 10-², which is quite high.

Therefore, the dissociation constant, ka, of HSO4- suggests that it is a strong acid.

Learn more about acid dissociation constant at: https://brainly.com/question/4363472

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Answer:

1s2 2s2 2p6 3s2 3p6

Explanation:

Chlorine is a groups 17 element. The halogens for ions by accepting one electron to form univalent negative ions.

Since chlorine normally contains seventeen electrons, the chloride ion consists of eighteen electrons.

Hence the electronic configuration of chlorine ion is; 1s2 2s2 2p6 3s2 3p6.

i) Las bacterias son organismos microscópicos unicelulares que prosperan en diversos entornos. Estos organismos pueden vivir en el suelo, el océano y dentro del intestino humano.

ii) Un virus es un agente infeccioso submicroscópico que se replica solo dentro de las células vivas de un organismo. Los virus infectan todas las formas de vida, desde animales y plantas hasta microorganismos, incluidas bacterias y arqueas.

Answer:

1 Ca(OH)2 + 2 HCl ---> 1 CaCl2 + 2 H2O

Answer:

Option A:

Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)

Explanation:

The half reactions given are:

Zn(s) → Zn^(2+)(aq) + 2e^(-)

Cu^(2+) (aq) + 2e^(-) → Cu(s)

From the given half reactions, we can see that in the first one, Zn undergoes oxidation to produce Zn^(2+).

While in the second half reaction, Cu^(2+) is reduced to Cu.

Thus, for the overall reaction, we will add both half reactions to get;

Zn(s) + Cu^(2+) (aq) + 2e^(-) → Cu(s) + Zn^(2+)(aq) + 2e^(-)

2e^(-) will cancel out to give us;

Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)

Answer:

ii and iv

Explanation:

atomic mass is the sum of protons and neutrons

protons ( postively charged) usually have the same number like electrons( negatively charged)

Answer:

0.20 mol

Explanation:

Let's consider the reduction of iron from an aqueous solution of iron (II).

Fe²⁺ + 2 e⁻ ⇒ Fe

The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:

5.6 g × 1 mol/55.85 g = 0.10 mol

2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are

0.10 mol Fe × 2 mol e⁻/1 mol Fe = 0.20 mol e⁻

0.20 mol of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)

 The reduction of iron from an aqueous solution of iron (II).

[tex]Fe^{+2} +2e^{-} \rightarrow Fe[/tex]

The formula for number of moles is as follows:-

[tex]Number \ of \ moles=\frac{Mass}{Molar\ mass}[/tex]

The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:

[tex]5.6 g \times\frac{1\ mol}{55.85\ g} = 0.10 \ mol[/tex]

2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are:-

[tex]0.10 mol Fe\times\frac{2\ mol\ e^{-} }{1\ mol\ e^{-}} = 0.20 \ mol e^{-}[/tex]

Hence, 0.20 mol of electrons is required to deposit 5.6g of iron.

To know more about:-

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Answer:

Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1  

Empirical formula is [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex].

Explanation:

The chemical formula of a hydrate  

Moles of anhydrous [tex]KAl(SO_{4} )_{2}[/tex]  

Molar mass of [tex]KAl(SO_{4} )_{2}[/tex] = 258.21 g /mol  

Mass of anhydrous [tex]KAl(SO_{4} )_{2}[/tex] = [mass of aluminum cup + alum after 2nd heating] –[ mass of empty cup]  

                                                   = 3.5 g – 2.4 g  

                                                   = 1.1 g

Moles of [tex]KAl(SO_{4} )_{2}[/tex]= mass / molar mass  

                                    = 1.1 g / 258.21 g per mol  

                                   = 0.00426 mol [tex]KAl(SO_{4} )_{2}[/tex]

The mole ratio of the H2O to [tex]KAl(SO_{4} )_{2}[/tex]

Mole ratio = moles of H2O/ moles of [tex]KAl(SO_{4} )_{2}[/tex]

                  = 0.05 mol H2O / 0.00462 mol [tex]KAl(SO_{4} )_{2}[/tex]

                 = 11.7

We can round the 11.7 to closest whole number = 12

Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1  

Empirical formula = [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex]  

So we have 12 moles of water as the water of hydration in the empirical formula.  

Alum hydrate is that the white crystalline solid after heating it'll start melting due to the water of hydration present in it then again solid will remain within the aluminum cup once all the water is given off within the sort of vapors.  

b) if the scholar used 2.20 g of the sample but within the calculation, he started with 2.0 g sample then  

when the mass of water is calculated using this data the mass of water is going to be higher therefore it gives more moles of water within the hydrate.  

So the final answer is going to be artificially high.

Answer:

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Explanation:

Answer:

A balanced chemical equation must always include coefficients on every reactant and product.

Explanation:

A balanced chemical equation does not need to include coefficients on every reactant and product.

For example, below is a balanced chemical equation in which the reactants and the products have no coefficients whatsoever:

NaOH(aq) + HCl (aq) -----> NaCl (s) + H2O (l)

Of course, a properly written chemical equation must include the states of matter of all the substances in the reaction and the number of atoms of each element must balance both in the reactant and product sides of the equation. Generally, a balanced chemical equation must obey the law of conservation of matter which opines that matter can neither be created nor destroyed but can only be converted from one form to another.

Hence, that a balanced chemical equation must always include coefficients on every reactant and product is not true.