what do you understand by valency electron and valency shell?​

Answer:

The columns of the periodic table are called groups. Members of the same group in the table have the same number of electrons in the outermost shells of their atoms and form bonds of the same type. The horizontal rows are called periods.

Answer:

At the plate boundary, there would be a divergent boundary where we can see a mid ocean ridge and a gap. We would be able to see the mantle because there would be a fissure from where magma will rise and solidify.    

Explanation:

Under the South American plate and African plate, there are currents that cause a divergent boundary. They create this boundary since they pull the tectonic plates apart, causing a mid-ocean ridge with an opening that allows the rising of the magma that was underneath. Once that the magma is out, it solidifies, and the currents will try to create another ridge to repeat the process.

When the plates are apart, the mantle that is beneath is exposed, and we can see the magma.

Answer:

2 % de cafe, 20% de azucar, 100% de agua.

Explanation:

Un clásico problema de soluciones:

- Nuestros solutos son 4 g de cafe y 20 g de azúcar.

- en 200 mL de agua

Podemos asumir que los 200mL es el volumen de solución.

%m/v es un tipo de concentración que señala los gramos de soluto en 100 mL de solución.

% m/v de cafe →  (4/200) . 100 = 2 %

% m/v de azucar →  (20/200) . 100 = 20 %

Si tomamos al agua como sustancia que forma parte de la solución sería

(200/200) . 100 = 100 %

Lo que podríamos leer 100 g de agua en 100 mL de agua, dado que la densidad del agua es 1 g/mL

Answer:

Multicellular Organisms.

Explanation:

Hi

Answer:

C

Explanation:

75 mile shallow flat area just off coastlines

do you have some examples or options to answer ?

Answer:

the molecules in the reactants interact to form new substances.

Explanation:

Answer:

it would break when it hits the ground

Explanation:

Answer:

A)The total number of protons plus neutrons= Weight of an atom

Answer:

A solubility chart with a list of ions

Explanation:

when mixed with other ions, they can become precipitates or remain aqueous. The following chart shows the solubility of multiple independent and various compounds, in water, at a pressure of 1 atm and at room temperature (approx. 293.15 K).

Answer:

it tells which compounds will dissolve in water

Explanation:

a p e x :)

Answer:

latent heat of condensation will have the same absolute value as the latent heat of vaporization. The latent heat of condensation will be negative. The latent heat of condensation is a characteristic property that can be used to identify a substance.

Explanation:

Answer:

energy absorbed or released by a substance during a change in its physical state (phase) that occurs without changing its temperature.

Explanation:

Answer:

C

Explanation:

To hello fight disease

Answer:

Explanation:

Given data:

Mass of alcohol = 400 g

Specific heat capacity of alcohol = 2.43 J/g°C

Initial temperature of alcohol = 16°C

Mass of water = 400 g

Specific heat capacity of water = 4.19 J/g°C

Initial temperature of water = 85°C

Final temperature of mixture = ?

Solution:

Equation:

m₁c₁ (T₂-T₁ ) = m₂c₂(T₂-T₁)

by putting values,

400 × 4.19  × (T₂ -  85°C) = 400 × 2.43  × (T₂ - 16°C)

1676  × (T₂ -  85°C) = 972 × (T₂ - 16°C)

Answer:

Mass = 12.27 g

Explanation:

Given data:

Mass of NaCl are required = ?

Volume of AgNO₃ = 346 mL (346 mL× 1L/ 1000 mL = 0.346 L)

Molarity of AgNO₃ = 0.607 M

Solution:

Chemical equation:

NaCl  + AgNO₃     →    NaNO₃ + AgCl

Number of moles of AgNO₃:

Molarity = number of moles / volume in L

0.607 M = number of moles / 0.346 L

number of moles =  0.607 M × 0.346 L

number of moles =  0.21 mol

now we will compare the moles of NaCl and AgNO₃.

                       AgNO₃         :          NaCl        

                           1                :            1

                       0.21              :            0.21

Mass of NaCl:

Mass = number of moles × molar mass

Mass = 0.21 mol × 58.44 g/mol

Mass = 12.27 g

Answer:

33.085476 meV ≈ 33 meV

Explanation:

Hope this helped!

Answer:

An acid is the specie which can donate a proton.

Explanation:

Bronsted lower acid:

An acid is the specie which can donate a proton.

Bronsted lower base:

A base is the specie that can accept the proton.

For example:

HCl + NH₃     →       NH₄⁺ + Cl⁻

Here in this reaction HCl is act an acid because it donate the proton while NH₃ is Bronsted lower base because it accept the proton.

Bronsted lowery acid = proton donor

Bronsted lowery base = proton accepter

Answer:

B) we will convert the 10 g of NaCl into moles.

Explanation:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

we will convert the 10 g of NaCl into moles.

Number of moles of NaCl:

Number of moles = mass/molar mass

Number of moles = 10 g/ 58.44 gmol

Number of moles = 0.17 mol

1 Kg = 1 L

Molarity = 0.17 mol / 2 L

Molarity = 0.085 mol/L

Molarity = 0.085 M

Answer:

B. Convert the 10g of NaCl to moles of NaCl

Answer:

0.59 g

Explanation:

The reaction at the first cathode;

Ag^+(aq) + e -----> Ag

if Q = It = 1.5 * 10 * 60 = 900C

According to Faraday's second law of electolysis; if we pass the same quantity of electricity through different electrolytes, the mass of substances deposited on each cathode is proportional to the equivalent weights.

Equivalent weight E = Atomic mass/valency

For Ag = 108/1 = 108

For Ni = 59/2 = 29.5

Hence

Let m1 = mass of Ag deposited =2.16

Let m2 = mass of Ni deposited

Let E1 = equivalent weight of Ag

Let E2 = equivalent weight of Ni

m1/m2 = E1/E2

2.16/m2 = 108/29.5

m2 = 2.16 * 29.5/108

m2 = 0.59 g

Answer:

1s^2   2s^2   2p^6    3s^2    3p^6    4s^2    3d^10   4p^6    5s^2    4d^2

Explanation:

Answer:

Explanation: Elements in group 14 have 4 valence electrons. Meaning that to achieve a stable octet they need to either gain or lose 4 electrons in total. That would take significantly more energy than other elements, e.g., group 1 (alkaline metals) or group 17 (halogens.)

Explanation:

In the periodic table, the elements in column 4 have four valence electrons and are less reactive compared to s- block elements but more reactive than the p-block elements.

Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.

It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.

Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.

Learn more about periodic table,here:

https://brainly.com/question/11155928

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Number of moles = 78.41

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

4.72 x 10²⁵ atoms of a substance, then moles :

[tex]\tt n=\dfrac{N}{No}\\\\n=\dfrac{4.72\times 10^{25}}{6.02\times 10^{23}}\\\\n=78.41[/tex]

N2+3H2-->2NH3

first we find the number of nitrogen moles

the molar mass for N2 is 14+14=28g/mole

to find the number of moles we divide the mass by the molar mass

n=400/28=14.28 moles

for 1 mole of N2 we use 3 moles of H2, therefore for 14.28 moles of N2 we use 14.28*3=42.84 moles ofH2

to find the mass of H2 we multiply the number of moles by the molar mass

the molar mass of H2 is 2g/mole

2*42.84=85.68g of H2

Answer:

b.

Explanation:

As the ozone layer is essential for nullifying the rays of the sun, without it there would be much more UV radiation.

Answer:

A. all other bulbs will no longer work

Answer:

young soil has less organic materiel that old

Explanation:

Answer:

d is the correct answer

Explanation:

Answer:

The carbon dioxide molecule is linear and centrosymmetric at equilibrium. The carbon–oxygen bond length is 116.3 pm, noticeably shorter than the bond length of a C–O single bond and even shorter than most other C–O multiply-bonded functional groups. Since it is centrosymmetric, the molecule has no electrical dipole.

Explanation:

Answer:

The carbon dioxide molecule is linear and centrosymmetric at equilibrium. The carbon–oxygen bond length is 116.3 pm, noticeably shorter than the bond length of a C–O single bond and even shorter than most other C–O multiply-bonded functional groups. Since it is centrosymmetric, the molecule has no electrical dipole.

Carbon dioxide | CO2 | CID 280 - structure, chemical names, physical and chemical ... It is a one-carbon compound, a gas molecular entity and a carbon oxide. ... Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. ... These actions are exploited clinically in the use of hyperventilation to diminish ...

Molecular Formula: CO2

PubChem CID: 280

Molecular Weight: 44.009 g/mol

Chemical Safety: Laboratory Chemical Safety