Define symbole and valeny.​

Answers

Answer 1

Answer:

Chemical symbol

This is used to identify an element without having to write the full name and as such is a designation for the element. It is used in chemical reactions and is usually either one or two letters. Some symbols are, Iron - Fe, Hydrogen - H and Oxygen - O.

Valency

This refers to the capacity of an element to combine with another to form a compound. It is measured by the number of electrons that an atom of an element gains, looses or shares when a chemical reaction involving it takes place.


Related Questions

Characteristics of the water at the mountain source: Speed: Temperature Oxygen Level Nutrient Level

Answers

Describe the characteristics of the water at the mountain source:

Answer:

The answer is below

Explanation:

Speed: there will be faster speed due to the steep slope movement of water from the mountain.

Temperature: there will be lower temperatures as a result of the faster speed of water movement which reduces the influence of solar radiation on it.

Oxygen: the oxygen content is higher due to little or no residue particles present in it.

Nutrient Level: this is considered somewhat low as a result of the water coldness and speed which does not support the nutrition base to form.


Which term means that a metal can be made into wire?
A)
Luster
B)
Ductility
Malleability
D)
Conductivity

Answers

Answer:

c

Explanation:

i think

What is a net ionic equation?
A. An equation that is balan
B. An equation that shows a

Answers

the answer should be b

Answer:

Explanation:

An equation showing only what is involved in the reaction.

a o e x

If you have 2 of the same substance and they are at the same temperature but have a different amount, what changes?

Answers

Answer:

The heat energy stored within them changes

Explanation:

Heat energy is a function of the mass of a body, its specific heat capacity, and its temperature.

In this case, the bodies have the same specific heat capacity since they are made from the same material and the same temperature.

To get the quantity of heat stored in a body, we need to multiply all three parameters as shown below

[tex]Q = mC \Delta T[/tex]

An increase in mass, through an increase in the amount of substance of a material present, will cause a corresponding increase in the heat energy stored within the material

determine the frequency and wavelength (in nm) of the light emitted when the e- fell from n=4 and n=2

Answers

Answer:

Frequency = 6.16 ×10¹⁴ Hz

λ = 4.87×10² nm

Explanation:

In case of hydrogen atom energy associated with nth state is,

En =  -13.6/n²

For n = 2

E₂ = -13.6 / 2²

E₂ = -13.6/4

E₂ = -3.4 ev

Kinetic energy of electron = -E₂ = 3.4 ev

For n = 4

E₄ = -13.6 / 4²

E₄ = -13.6/16

E₄ = -0.85 ev

Kinetic energy of electron = -E₄ = 0.85 ev

Wavelength of radiation emitted:

E = hc/λ = E₄ - E₂

hc/λ = E₄ - E₂

by putting values,

6.63×10⁻³⁴Js × 3×10⁸m/s / λ = -0.85ev   - (-3.4ev )

6.63×10⁻³⁴ Js× 3×10⁸m/s / λ = 2.55 ev

λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s  /2.55ev

λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s  /2.55× 1.6×10⁻¹⁹ J

λ = 19.89 ×10⁻²⁶ Jm / 2.55× 1.6×10⁻¹⁹ J

λ = 19.89 ×10⁻²⁶ Jm / 4.08×10⁻¹⁹ J

λ = 4.87×10⁻⁷ m

m to nm:

4.87×10⁻⁷ m ×10⁹nm/1 m

4.87×10² nm

Frequency:

Frequency = speed of electron / wavelength

by putting values,

Frequency = 3×10⁸m/s /4.87×10⁻⁷ m

Frequency = 6.16 ×10¹⁴ s⁻¹

s⁻¹ = Hz

Frequency = 6.16 ×10¹⁴ Hz

Help ASSSAPPPP I WILL MARK BRAINLIEST. What is the outer electron configuration for tin?

Answers

Answer:

hope this helps!

Tin atoms have 50 electrons and the shell structure is 2.8. 18.18. 4.


I hope this helps!

Clay and Pumice have pores but the pores are not well connected. If you poured water over either of them it would just run off the surface. It wouldn't run through. But they could hold water in their pores. We can say then that both or them ARE ___________________ but NOT __________________________________.

Answers

Answer:

Clay and Pumice can both be said to be Porous but they are not Permeable

Explanation:

A porous substance is one which have pores in in through which air or liquid can pass through. Both clay and pumice are porous due to the presence of pores in them. These pores allow air to pass through them. However, since the pores are not well connected water do no pass through them. As a result, clay vessels can hold water within them and pumice floats on water.

Permeability is the ability of a substance to allow other substances to pass through. Both clay and pumice have low permeability, as a result they do not allow water to pass through them. Rather, water runs over their surface when poured over them.

Answer:

Clay and Pumice can both be said to be Porous but they are not Permeable

Explanation:

Name 3 types of rock on Planet Earth.

Answers

Answer:

igneous, sedimentary, and metamorphic

Explanation:

Answer:

IGNEOUS ROCKS form when molten rock (magma or lava) cools and solidifies. SEDIMENTARY ROCKS originate when particles settle out of water or air, or by precipitation of minerals from water.

And METAMORPHIC (I dont have nothing for this won)

Explanation:

Hello there please help this is for science and if you answer thanks for the help you earned yourself a 5 star.

Answers

Answer:

Ice cubes, glass of tea, and butter

Explanation:

Like it said in the hint, the molecules will only speed up if they gain heat. This means in order for the object to heat up it will have to have a temperature that is less than the temperature in the room. Ice cubes, glass of tea, and butter are the three objects that have a temperature less than 72 degrees so when they are placed in the 72 degrees room they will heat gain heat (therefore making the molecules move faster)

HELP!!!
find the balanced equation​

Answers

Answer:

3Fe²⁺ + Cl₂ ⇒ 2Fe³⁺ + 2Cl⁻

Explanation:

manipulate the problem to match charges and have the same amount of reactants and products on both sides.

Why doesn’t the nucleus fly apart?

Answers

A strong force - called the strong nuclear force - holds protons and neutrons together in the nucleus.

Which two statements are true about redox reactions?
A. They include both oxidation and reduction reactions,
B. Electrons are transferred.
C. They are double-replacement reactions.
D. They are acid-base reactions,

Answers

Answer:

A. They include both oxidation and reduction reactions AND B. Electrons are transferred.

Explanation:

a p e x

The statements that are true about redox reaction are:

A. They include both oxidation and reduction reactions,

B. Electrons are transferred.

What is a redox reaction?

The Redox reaction is the one in which oxidation and reduction take place simultaneously. In this process transfer of electrons takes place which further leads to oxidation or reduction.

Thus, options A and B are correct.

Find more information about Redox reaction here:

brainly.com/question/21851295

group viia elements are very active non metals give reason​

Answers

Answer:

because they need only one electron

point Deshawn ran the 400 m race(in a straight line) in 2 minutes. What is his distance and displacement ? Explain your answer below in complete sentences.​

Answers

His distance and displacement are the same, which was 400 m

Further explanation

Given

Distance = 400 m

time = 2 min

Required

Distance and displacement

Solution

Distance is a scalar quantity that indicates the length of the trajectory that is traveled by an object within a certain interval. Distance has no direction, only has magnitude  

Can be simplified distance = totals traveled  

Displacement is a vector quantity that shows changes in the position of objects in a certain interval of time. Displacement has magnitude and direction  

Can be simplified displacement = distanced traveled from starting point to ending point  

From the definition above shows that the displacement and the distance that he traveled have the same value (magnitude), which is equal to 400 m

The value of the two will be different if he starts and finishes at the same point, then the displacement value is zero while the distance he has traveled is still 0

the characterstic part of a molecule that determines its chemical properties is known as​

Answers

Answer: The atomic number indicates the number of protons within the core of an atom. The atomic number is an important concept of chemistry and quantum mechanics. An element and its place within the periodic table are derived from this concept. ... These electrons mainly determine the chemical behaviour of an atom. The chemical properties of an element, are determined by the number of protons in the nucleus. This number of protons is called the atomic number. The mass of the atom, its atomic mass, depends upon the sum of the number of protons and the number of neutrons present in the nucleus.

Hope this helps....... Stay safe and have a Merry Christmas!!!!!!! :D

Explanation:

Outer Electrons/Valence Electrons determine the chemical properties....Or Somehow we can say in organic compounds, functional group determine mostly chemical properties...

2. what is the molarity of a 300ml solution which is 25%by mass H2S04?
the solutions mass is 353.4g

Answers

Answer:

3 M

Explanation:

Molarity is calculated by dividing the moles of the solute by the liters of solution. In this problem, we are given that the mass of the solution is 353.4 g and that the mass of the solute (H2SO4) is 25% of this.

Thus, you get that the mass of the solute is 88.35 g.

Next, you must convert the mass of the solute into moles. You must use the periodic table to find the molar mass of the solute in order to do the conversion.

Thus, you get that the number of moles of solute is 0.90.

Molarity is then = 0.90 mol/.300 L = 3 M.

The molarity of a 300ml solution of mass 353.4 g which is 25%by mass H₂SO₄ is 2.94 molar.It is calculated from the number of moles of sulphuric acid.

What is molarity?

Molarity is a term used to represent the concentration of a solution. Mathematically it is the ratio of the number of moles of solute to the volume of solution in liter.

The mass percent of substance is the ratio of mass of that substance to the total mass. Here, the total mass of the solution is 353.4 g and the solute acid is 25% by mass. Thus mass of the solute is :

353.4 × 25 /100 = 88.3 g.

The molar mass of sulphuric acid is 100 g/mol. Thus number of moles of solute is 88.3 g/100 g/mol = 0.88 moles.

The volume of the solution is 300 ml or 0.3 liter. Now, the molarity of the solution can be calculated as follows:

Molarity = no.of moles of solute/volume in L

              = 0.88 mol / 0.3 L

              = 2.94 mol/L.

Hence, the molarity of the solution is 2.94 molar.

To find more about molarity, refer the link below:

https://brainly.com/question/4401006

#SPJ2

How many moles are in 34.2 g Ca

Answers

Answer:

0.855 moles are present in 34.2 g of Ca

Which of the following double-replacement reactions will occur?

NaBr(aq) + AgNO3(aq) →

NaBr(aq) + Ca(NO3)2(aq) →

NaBr(aq) + Al(NO3)2(aq) →

NaBr(aq) + KNO3(aq) →

Answers

NaBr(aq) + AgNO3(aq) →NaNO3(aq) + AgBr(s)⇒ double-replacement reactions will occur

Further explanation

Double-Replacement reactions. Happens if there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product

A double replacement reaction will occur if one or both of the products is an insoluble precipitate, a liquid, or a gas

To predict whether this reaction can occur or not is one of them, the precipitation reaction. A precipitation reaction occurs if two ionic compounds which are dissolved reacted to produce one of the products of the ion compound does not dissolve. Formation of these precipitating compounds that cause reactions can occur

Solubility Rules:

• 1. soluble compound

All compounds of Li +, Na +, K +, Rb +, Cs +, and NH4 +

All compounds of NO₃⁻ and C₂H₃O₂⁻

Compounds of Cl−, Br−, I− except Ag⁺, Hg₂²⁺, Pb²⁺

Compounds of SO₄²⁻ except Hg₂²⁺, Pb²⁺, Sr²⁺, Ba²⁺

• 2. insoluble compounds

Compounds of CO₃²⁻ and PO₄³⁻ except for Compounds of Li +, Na +, K +, Rb +, Cs +, and NH₄ +

Compounds of OH− except Compounds of Li +, Na +, K +, Rb +, Cs +, NH₄⁺ , Sr²⁺, and Ba²⁺

NaBr(aq) + AgNO3(aq) →NaNO3(aq) + AgBr(s)⇒ occur

NaBr(aq) + Ca(NO3)2(aq) → NaNO3(aq) + CaBr₂(aq)⇒not occur

NaBr(aq) + Al(NO3)3(aq) →NaNO3(aq) + AlBr3(aq)⇒not occur

NaBr(aq) + KNO3(aq) →NaNO3(aq) + KBr(aq)⇒not occur

Which is not true of the ideal gas law?

-For a given amount of gas held at constant temperature, the product of pressure and
volume is constant.

-It describes the behavior of an ideal gas in terms of the pressure, volume,
temperature, and number of moles of gas present.

-None of the above.

-The value of R is 0.082.1 L.atm/mol.K.

Answers

Answer:

For a given amount of gas held at constant temperature, the product of pressure and

volume is constant.

:

28. Which of the following statements is TRUE about acids and bases
A. Acids and bases do not react with each other
B Acids mixed with bases neutralize each other
C Acids mixed with bases make stronger bases
D. Acids mixed with bases make stronger acids
hont to flow called?​

Answers

Answer:

B. Acid mixed with bases neutralize each other

Answer:

Hey buddy, here is your answer. Hope it helps you.

Explanation:

B- Acids mixed with bases neutralize each other. Acid + base ——-> salt+water solution. Mixing these two will make them neutralize .

When a car burns gas most of the energy is lost as heat. This inefficiency of energy transfer is an example of which law of energy?

A. second
B. fourth
C. first
D. third

Answers

Answer:

C) first

Explanation:

Imagine that you have an ideal gas in a 4.30 L container, and that 1250 molecules of this gas collide with a square-inch area of the container at any given instant. If the volume is increased to 21.5 L at constant temperature, how many collisions will occur per square inch of this larger container

Answers

Answer:

250 collisions per square inch

Explanation:

According to Boyle's law, at constant temperatures, the pressure exerted by gas molecules is inversely proportional to the volume of the gas. Hence;

    P1V1 = P2V2 where P1 = initial pressure, V1 = initial volume, P2 = final pressure, and V2 = final volume

In this case, the collision that occurred is taken as the pressure.

P1 = 1250, V1 = 4.30 , V2 = 21.5 P2 = ?

P2 = P1V1/V2

        = 1250 x 4.30/21.5

                 = 250

Hence, at a constant temperature, 250 collisions per square inch of the larger container will occur.

MARKING BRAINLIEST! AND 16 POINTS

Plants use energy from sunlight, water, and carbon dioxide to produce sugar. What structure is found only in plant cells and helps plants capture energy from sunlight?

Answers

Answer:

Chloroplast.

Explanation:

Answer:

chlorophat

Explanation:

How many moles of CO2 can form from 5.1 moles of C3H8 and abundant O2 in the equation:
C3H8 + 5O2 -> 3CO2 + 4H2O

Answers

Answer:

15.3 moles of CO₂ formed.

Explanation:

Given data:

Number of moles of CO₂ formed = ?

Number of moles of C₃H₈ react = 5.1 mol

Solution:

Chemical equation:

C₃H₈ + 5O₂       →     3CO₂ + H₂O

Now we will compare the moles of CO₂ with C₃H₈.

                          C₃H₈         :          CO₂

                              1            :            3

                             5.1          :         3/1×5.1 = 15.3 mol  

1. Which type of blood cell is the most numerous in the body?
O a. red blood cells
O b. white blood cells
c. platelets
d. plasma

Answers

Answer:

red blood cells

Explanation:

I'm not so sure though

How many valence electrons does Florine have?
O 5
O 7
3
9

Answers

Answer:

When forming ions, elements typically gain or lose the minimum number of electrons necessary to achieve a full octet. For example, fluorine has seven valence electrons, so it is most likely to gain one electron to form an ion with a 1- charge

Explanation:

Answer:

7

Explanation:

a-P-e-X

Can gravity be considered a force?

Answers

Answer: Gravity is considered a universal force because it acts between any two masses anywhere in the universe.

Answer:

Gravity (from Latin gravitas 'weight'[1]), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light[2]—are brought toward (or gravitate toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides.

limitation of hydrogen displacement method​

Answers

Answer:

Limitation of hydrogen displacement method​  is described below in detailed explanation.

Explanation:

This approach is beneficial for elements that can displace hydrogen from psychedelics or can consolidate with hydrogen. A single replacement effect, sometimes described as a single displacement reaction, is a reflection in which one component is replaced for a different component in a compound. The origin elements are forever pure elements, such as a clear zinc metal or hydrogen propellant, plus an aqueous compound.

Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm8 at 27 ∘C. (R = 0.083 bar dm8 K−1 mol−1​

Answers

Answer:

Total pressure =  56.77 bar

Explanation:

Given data:

Mass of dioxygen = 8 g

Mass of dihydrogen = 4 g

Volume of vessel = 1 dm³

Temperature = 27°C (27+273 = 300 K)

R = 0.083 bar.dm³ / mol.K

Total pressure = ?

Solution:

Number of moles of dioxygen:

Number of moles = mass/molar mass

Number of moles = 8 g/ 32 g/mol

Number of moles = 0.25 mol

Pressure of dioxygen:

PV = nRT

P = nRT/V

P = 0.25 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³

P = 6.97 bar.dm³  /1 dm³

P = 6.97 bar

Number of moles of dihydrogen:

Number of moles = mass/molar mass

Number of moles = 4 g/ 2 g/mol

Number of moles = 2 mol

Pressure of dihydrogen:

PV = nRT

P = nRT/V

P = 2 mol × 0.083 bar.dm³ / mol.K × 300 K / 1 dm³

P = 49.8 bar.dm³  /1 dm³

P = 49.8 bar

Total pressure of mixture in a vessel:

Total pressure = P (O₂) + P(H₂)

Total pressure =  6.97 bar + 49.8 bar

Total pressure =  56.77 bar

CAN SOMEONE HELP ME ON THIS!!! THIS IS VERY URGENT

Answers

Answer:

Explanation:

3: Given data:

Number of moles of strontium nitrate = 3.00×10⁻³ mol

Number of atoms = ?

Solution:

There are 9 moles of atoms in 1 mole of Sr(NO₃)₂.

In 3.00×10⁻³ moles,

9 mol × 3.00×10⁻³

27.00×10⁻³ mol

Number of atoms in 3.00×10⁻³ mol of Sr(NO₃)₂:

27.00×10⁻³ mol × 6.022×10²³ atoms / 1mol

162.59×10²⁰ atoms

4)Given data:

Mass of calcium hydroxide = 4500 Kg (4500/1000 = 4.5 g)

Number of moles = ?

Solution:

Number of moles = mass in g/molar mass

by putting values,

Number of moles = 4.5 g/ 74.1 g/mol

Number of moles = 0.06 mol

5) Given data:

Number of atoms of silver nitrate = 1.06×10²³

Number of moles = ?

Solution:

1 mole of any substance contain  6.022×10²³ atoms .

1.06×10²³ atoms × 1 mol /  6.022×10²³ atoms

0.176 moles of silver nitrate

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Melanies smartphone has 48 apps. This is 4 times the number of apps Priscilla and Cynthia have altogether on their phones. If Cynthia has 5 apps, how many apps does Priscilla have?Complete the steps below to solve for the number of apps on Priscillas smartphone.A -Write a numerical expression to represent the number of apps Priscilla and Cynthia have combined. (Do not simplify the expression just yet.)B -Cynthia has 5 apps. Write a numerical expression that represents the number of apps Priscilla has. Refer to the expression you wrote in part A.C -Simplify the expression from part B to find the number of apps Priscilla has.D -You just worked with numerical expressions. Now let's try an equation. Let p be Priscillas number of apps. Write an equation in terms of p to represent the problem.E -Solve the equation you found in part D. What is the value of p? Show your work.F -You solved the problem using two methods: numerical expressions and an equation with variable p. Did you use the same sequence of operations in both methods?H -What does your answer to part F imply? Explain. DESCRIBE the six classes of nutrients IN GENERAL. Then pick TWO and give asmuch detail about them as possible including their sources. Please help me solve m A biologist is surveying the animal life found in the deciduous forests of the Adirondack Mountains in New York. He spots a mother black bear and cubs, a herd of white-tailed deer, 15 bird species, and two species of trout. Beneath decaying logs, he discovers insects, termites, salamanders, and earthworms. Which describes the variety of animals surveyed by the biologist.PLS ANSWEROnly invertebrates were surveyed in the forest.Only vertebrates were surveyed in the forest.Vertebrates and invertebrates were surveyed in the forest. how many times greater is 3.4 times 10^5 than 2 times 10^3 Who invented smores?(Will Mark Branliest!)*And answer something other than the Girl Scouts please Canned food available for sale at grocery stores have been subjected to a commercial canning process. If you bought a can of peas from the local grocery store and found the peas to be spoiled, it could explained by At the beginning of Act 2, John Proctor says to Elizabeth: "It's winter in hereyet. On Sunday let you come with me, and we'll walk the farm together."What is Miller implying about their relationship through this quote? *O John has decided to leave Elizabeth.O John thinks Elizabeth should be helping more at home.There is tension between the two of them.O They have never been close. Translate the words in brackets. He [sends us to you (plural)].A. se los enviaB. les nos enviaC. les se enviaD. nos les envia i. Name and describe two options in Orientation. if you were given the following statements write your conclusion : A bird goes from a higher location to a lower location at a rate of 3 meters per second. Which equation models the change in the bird's position at 120 seconds?a. 120(-3) = -360b. 120 x 3 = 360c. (-120)(-3) = -360d. 120(-3) = 360 certain things that we lose at times come back to us even after years give reason Rectangle LMNP was dilated using the rule DP,3. Which statements are true? Check all that apply. The length of line segment M'N' is 18 units. The length of segment M'N' is 14 units. The dilation is a reduction. The dilation is an enlargement. The scale factor is One-third. The scale factor is 3. If a normal distribution has a mean of 62 and a standard deviation of 12, whatis the z-score for a value of 74? I NEED HELP ASAP LIKE RIGHT NOW BECAUSE I DON'T KNOW THIS!!!List and describe one foreign policy event from the first five Presidents. I am traveling at 100 m/s, I hit the brakes and my speed goes down to 50 m/s. It took 30 seconds to slow down. What was my acceleration?A.5 m/s2B.-5 m/s2C.1.7 m/s2D.-1.7 m/s2 X^2 + 6x + 16y - 23 = 0What is the standard form of the equation? It can be understood that Coney Island, Navy Pier, and the Santa Monica Pier are all examples of The formula for the volume of a cone is v= 1/3 xr^2 h. The radius, r, of the cone may be expressed as