write down the uses of periodic table। ​

Answer:

0.245 moles

Explanation:

moles of lithium = 2*moles of Li2SO4

so moles of LI2SO4=2.94*10^23/(2*6*10^23)=0.245

One mole of lithium sulphate contains 1.2 .022 × 10²⁴ atoms. Thus, the number of moles of this compound which contains 2.94 × 10²³ Li atoms is 4.08 moles.

Any substance containing 6 .022 × 10²³ number of atoms is called one mole of that substance. This number is called Avogadro number. Hence, one mole of every elements or molecules contains Avogadro number of atoms.

Similarly, one mole of any compound contains 6 .022 × 10²³ molecules. The weight of one mole of a compound is called its molar mass. The mass of one mole of an element is called its atomic mass.

Hence, one mole of lithium sulphate contains 2 × 6 .022 × 10²³  atoms of lithium. Therefore, the number of moles of lithium sulphate containing 2.94 × 10²³ Li is :

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40

Explanation:

because its Saturated

Answer:

sublimation

Explanation:

Answer:

A, Cardiovascular system

cardiovascular system

Explanation:

here's the answer to your question about

Answer:

tác dụng với acid,

Explanation:

Answer:

Having high melting point.

Explanation:

The original product has high melting point as compared to the mixture product because in the original product, the element is present in its pure state and we know that pure substances have high melting point as compared to mixture substances due to the presence of strong intercellular forces between them which is hard to break so that's why we can say that the original product has high melting point.

Answer:

Any individual offspring produced through asexual reproduction is always: genetically identical to its parent. made up of cells with a cell wall. different from all of its siblings

Explanation:

The given molecule is

H3C - C ≡ C - CH3

The numbering order is shown below:

H3C - C ≡ C - CH3

    1     2     3     4

So, the alkyne group is in the second position.

The carbon chain has four carbons.

Hence, the IUPAC name of the given compound is:

2-butyne.

Answer:the element is potassium

the proton and electron is 19 and the nuetron is 19

Explanation:

Answer:

The atomic number gives the number of protons 19

p = 19

The atomic mass is the sum of the protons and neutrons

p+n = 39 p = 19

Put p into the equation and solve for n the neutrons

19+n = 39

Subtract 19 from both sides

19-19+n = 39-19

n = 20

The number of electons equal the number of protons in a neutral atom. The positive charge equal to the negative charge. The negative charge is the number of electons. This ion has a charge of +1. So solve for the negative charge.

-19+1 = -18

The negative charge is -18 so

e = 18

Answer:

C. Lithium

Explanation:

This image describes the trend in reactivity. Group 1 metals are always the most reactive so yeah :)

Answer:

Explanation:

The most prominent function of mitochondria is to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration and using sugar as fuel, and to regulate cellular metabolism .

Explanation:

This reaction is also known as double decomposition reaction.

HCl + CaCO3 + MgCO3 → H2O + H2 + CO2 + CaCl2 + MgCl2

Answer:

B

Explanation:

Pure water always has equal concentrations of hydrogen and hydroxide ions.

Answer:

C

electrons are negatively charged particles

Answer: D

Explanation:

just took the test

Answer:

Kinetic energy

Explanation:

Kinetic energy is the energy associated with an object's motion. It is mass and velocity dependent by a directly proportional relationship.

Potential energy is the energy associated with an object's position.

Thermal energy is the energy associated with heat addition or withdrawal.

Kinetic energy is the energy that a body possesses because of its movement, that is, it is the energy that arises when objects are in motion.

Therefore, we can conclude that kinetic energy is the energy produced by its movements that depends on its mass and speed.

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A. Coal

Others are animal remains

The fossil fuel which is the remains of ancient plants is: A. Coal.

Non-renewable energy can be defined as a type of energy that is mainly generated through artificial sources or from the remains of ancient plants.

Hence, a non-renewable energy cannot be replenished or renewed like the renewable energy sources.

Basically, some examples of a non-renewable energy include:

Coal deposits are typically petrified peat swamps and peat is generated from decaying plants.

Also, coal has been discovered to be a fossil fuel that contain the remains of ancient plants, based on radioactive dating.

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Answer:

Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. ... Extent, quality, or size as determined by measuring; dimension. A waist measurement of 32 inches.

Explanation:

The comparison o unknown quantity with known standard quantity is called measurement.

The thickness of one button will be 2mm

* N.B: We convert the height of the 12 buttons to same unit (mm)

Then, 2cm = 2 × 10 = 20mm

20mm + 4mm = 24mm

24/12 = 2mm thick

Hence, one button is 2mm thick.

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Answer:

Zn²⁺ + 2Ag → Zn + 2Ag⁺

Explanation:

According to the reduction potential chart, silver ion (Ag⁺) is a stronger oxidizing agent than zinc (Zn), which is a reducing agent the compared to silver

Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series

The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76

The reduction potential for Ag⁺ + e⁻ → Ag = +0.8

Given that redox reactions are reversible, we get the following likely redux reaction:

Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)

Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.

Answer: The average percent yield of MgO is 98.59 %.

Explanation:

The chemical equation follows:

[tex]2Mg(s)+O_2(g)\rightarrow 2MgO(s)[/tex]

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of Mg = 0.411 g

Molar mass of Mg = 24.3 g/mol

Plugging values in equation 1:

[tex]\text{Moles of Mg}=\frac{0.411g}{24.3g/mol}=0.0170 mol[/tex]

By the stoichiometry of the reaction:

If 2 moles of Mg produces 2 moles of MgO

So, 0.0170 moles of Mg will produce = [tex]\frac{2}{2}\times 0.0170=0.0170mol[/tex] of MgO

We know, molar mass of [tex]MgO[/tex] = 40.3 g/mol

Putting values in equation 1, we get:

[tex]\text{Mass of }MgO=(0.0170mol\times 40.3g/mol)=0.685g[/tex]

The percent yield of a reaction is calculated by using an equation:

[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)

Given values:

Actual value of the product = 0.675 g

Theoretical value of the product = 0.685 g

Plugging values in equation 1:

[tex]\% \text{yield}=\frac{0.675g}{0.685g}\times 100\\\\\% \text{yield}=98.54\%[/tex]

Hence, the % yield of the product is 98.54 %

Given mass of Mg = 0.266 g

Molar mass of Mg = 24.3 g/mol

Plugging values in equation 1:

[tex]\text{Moles of Mg}=\frac{0.266g}{24.3g/mol}=0.011 mol[/tex]

By the stoichiometry of the reaction:

If 2 moles of Mg produces 2 moles of MgO

So, 0.011 moles of Mg will produce = [tex]\frac{2}{2}\times 0.011=0.011mol[/tex] of MgO

We know, molar mass of  = 40.3 g/mol

Putting values in equation 1, we get:

[tex]\text{Mass of }MgO=(0.011mol\times 40.3g/mol)=0.443g[/tex]

The percent yield of a reaction is calculated by using an equation:

[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex] ......(2)

Given values:

Actual value of the product = 0.437 g

Theoretical value of the product = 0.443 g

Plugging values in equation 1:

[tex]\% \text{yield}=\frac{0.437g}{0.443g}\times 100\\\\\% \text{yield}=98.64\%[/tex]

Hence, the % yield of the product is 98.64 %

Average of a measurement is calculated by given formula:

[tex]Average=\frac{M_1+M_2}{2}[/tex]

where,

[tex]M_1[/tex] = percentage yield for Trial 1 = 98.54 %

[tex]M_2[/tex] = percentage yield for Trial 2 = 98.64 %

Putting values in above equation, we get:

[tex]Average=\frac{98.54+98.64}{2}=98.59\%[/tex]

Hence, the average percent yield of MgO is 98.59 %.

Ca(s)+ H2O (l)----->H2 +Ca(oH)2

Ca(s)+2H2O(l)----->H2(g)+Ca(oH)2

I hope this helps

sorry if it's wrong

Answer:

7.2

Explanation:

you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios

number of moles of calcium nitrate=mass/mm

=16.4/102

=0.16g/mol

then you use the mole to mole ratios

2 : 4

0.16: x

2x/2=0.64/2

x=0.32g/moles of nitrogen dioxide

then you use the formula for the volume

v=22.4n

=22.4×0.32

=7.2

I hope this helps

Answer:

A. The rate of reaction will increase or go up

B. The rate of reaction will decrase or go down.

Explanation:

Increasing the temperature will make the gas particles move faster. Faster movement will increase rate of collision between particles to cause a reaction. Decreasing the temperature will cause the opposite to happen.

Answer:

A. N2(g) + 3H2(g) Right arrow. 2NH3(g)

B.C(s) + 2H2(g) Right arrow. CH4(g)

Explanation:

Answer:

a and b

Explanation:

second question

miultiplu second eq by 2

Answer:

See explanation

Explanation:

Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.

In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.

Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.

Answer:

False  grams is not used

Explanation:

IDEAL GAS LAW

The ideal gas law states that PV = NkT, where P is the absolute pressure of a gas, V is the volume it occupies, N is the number of atoms and molecules in the gas, and T is its absolute temperature.  

It is necessary to use Kelvin for the temperature and it is conventional to use the SI unit of liters for the volume. However, pressure is commonly measured in one of three units:  kPa ,  atm , or  mmHg . Therefore,  R  can have three different values.

Answer:

.

Explanation:

Answer:

The modern periodic law states that the physical and chemical properties of the elements are the periodic function of the atomic numbers and electronic configurations. ... This repetition occurs if the arrangement of the elements is in order of their increasing atomic numbers.