How many valence electrons does this atom have? (Urgent)

Answer:

41.63g

Explanation:

Given parameters:

Volume of CaCl₂  = 500mL  = 0.5L

Concentration  = 0.75mol/L

Unknown:

Mass of the solute needed = ?

Solution:

The mass of the solute can be derived using the expression below;

     Mass  = number of moles x molar mass

But,

   Number of moles  = Concentration x Volume

So;

     Mass  = Concentration x Volume x molar mas

Molar mass of CaCl₂  = 40 + 2(35.5) = 111g/mol

     Mass  = 0.75 x 0.5 x 111 = 41.63g

the largest is francium, Z=87 , or caesium, Z=55 ; and the smallest is definitely helium, Z=2 .

Explanation:

make me Brainliest

Answer:

Physical change occur when objects or sub undergo a change that does not change their chemical composition.

Chemical change us a permanent change which occur when a substance combined with another to form a new substances.

Answer:

Condensation 212F or 100C, Freezing 32F or 0C

Explanation:

Condensation 212 degrees Fahrenheit or 100 degrees Celsius.

Freezing point 32 degrees Fahrenheit or 0 degrees Celsius.

Answer:

The percentage by mass of lithium in one mole of Li₃N is approximately 59.78%

Explanation:

The given compound is Li₃N

The atomic mass of lithium, Li = 6.94 amu

The atomic mass of nitrogen, N = 14.01 amu

Therefore by definition, we have;

The mass of one mole of lithium, Li = 6.94 g

The mass of one mole of nitrogen, N = 14.01 g

One molecule of Li₃N contains 3 atoms of lithium, Li and 1 atom of nitrogen, N

The mass of one mole of Li₃N = The molar mass of Li₃N = 3 × The mass of one mole of lithium + The mass of one mole of nitrogen

∴ The mass of one mole of Li₃N = 3 × 6.94 g + 14.01 g = 34.83 g

The percentage by mass of lithium, Li, in one mole of Li₃N = 3×6.94/(34.83) × 100 ≈ 59.78%

The percentage by mass of lithium in one mole of Li₃N ≈ 59.78%.

Answer:

AG

Explanation:

HOPE THIS HELPS

Answer:

The correct option is A

Explanation:

Radium is an atom with the atomic number of 88. It is a metal found in group 2 of the periodic table; meaning that it has two valence electrons in it's outermost shell. As a metal that wants to form an ionic compound, radium would have to lose these two valence electrons to become a divalent positively charged cation (Ra²⁺). Thus, the correct option is A

Answer:

ok

Explanation:

Answer:

It's called "Great conjunction"

Rate of  consumption of  N₂ = - 1.25 x 10⁻⁴

The reaction rate (v) shows the change in the concentration per unit time.  

[tex]\tt rate=\dfrac{concentration(M)}{time(s)}[/tex]

The rate reaction for Haber Bosch :

N₂(g)+3H₂(g)⇒2NH₃(g)

From equation, mol ratio N₂ : NH₃ = 1 : 2, so

the rate of formation of ammonia = 2 x the rate of consumption of nitrogen.

Given

the rate of formation of ammonia gas : 2.5x10⁻⁴ M/s

the rate of consumption of nitrogen :

[tex]\tt \dfrac{2.5\times 10^{-4}}{2}=1.25\times 10^{-4}[/tex]

The sign negative for consumption : -1.25 x 10⁻⁴ M/s

or we can use another way:

Rate of formation of  NH₃  = reaction rate x coefficient of  NH₃

2.5 x 10⁻⁴ = reaction rate x 2

reaction rate = 1.25 x 10⁻⁴

Rate of  consumption of  N₂  = reaction rate x coefficient of N₂

Rate of  consumption of  N₂ =  1.25 x 10⁻⁴ x 1

Rate of  consumption of  N₂ =  1.25 x 10⁻⁴

Answer:

Eclipse

Explanation:

Answer:

2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2

Explanation:

The balanced reaction equation is shown below;

2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2

This reaction is possible because the reduction potential of Rb is -2.98V while that of Ba is –2.92 V. Hence Rb can displace Ba from its salt solution.

The equation is balanced since the number of atoms of each element on the left and right hand sides of the reaction equation are equal.

The products for the reaction of Rubidium nitrite and Barium carbonate has been Barium nitrite and Rubidium carbonate.

Rubidium nitrite has been the binary ionic compound found to be acidic in nature. While barium carbonate has been the basic salt with the potency to be poisonous to humans.

The reaction between an acid and a base has been the neutralization reaction with the formation of salt and water. The reaction between rubidium nitrite and barium carbonate will be:

[tex]\rm 2\;RbNO_2\;+\;BaCO_3\;\rightarrow\;Rb_2CO_3\;+\;Ba(NO_2)_2[/tex]

The reaction has been the displacement reaction with the tendency to displacement.

For more information about displacement reaction, refer to the link:

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Answer: The statement that is not a determining factor in formation of intrusive igneous rocks is 'None of the above' and Magma cools very fast beneath the Earth's surface.

Explanation:

Rocks are naturally occurring solid materials that are made up of different types of minerals which affects it's texture and colours. The three main types of rocks are:

--> sedimentary rocks,

--> metamorphic rocks and

--> igneous rocks.

Igneous rocks are formed from the crystallization and solidification of hot molten rocks which originates from deep within the earth. Depending on where the molten rock solidifies, the igneous rock is divided into two, namely:

--> intrusive igneous rock and

--> extrusive igneous rock.

The INTRUSIVE IGNEOUS rocks are formed within or deep beneath the earth surface when the hot magma SLOWLY cools over millions of years until it solidifies. The slow cooling allows large crystals to grow.

Therefore the statements (None of the above and Magma cools very fast beneath the Earth's surface) are not a determining factor.

Answer:

a 17 bc it is how it works

Girls are usually completely physically mature by 18 years old.

Puberty refers to the physical transformation of a child's body into an adult one capable of fertile reproduction.

In girls puberty generally attains before two years earlier than the boys. And the exact age of the girls to attain puberty is in between the age of 10 to 14.

Hence the age of girls to attain puberty is 14.

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Answer:

high electrical and thermal conductivity

Answer:

Metals donate electrons.

They are good conductors of heat and electricity.

Answer:

importent factors

Explanation:

The salient facts about something or qualities of something are the most important things about them: She began to summarize the salient features/points of the proposal. The article presented the salient facts of the dispute clearly and concisely. SMART Vocabulary: related words and phrases. Very important or urgent.

Answer

The answer is a/important factors. Pls subscribe to Amiredagoat Yt in return.

Explanation:

Answer:

.

Explanation:

An element's location in the periodic table is largely depending on its electrons. The number of valence shell electrons determines its group, and the type of orbital in which the valence electrons lie in determines the element's block. Sometimes during these groups there are more like the alkali metals the non metals and gases :)

Answer:

Lithium,sodium, beryllium, aluminum form cations and the rest form anions

Explanation:

i think the question should be rephrased as 'which elements form cations".

Answer:

B. The coefficients give the molar ration of the reactants

Explanation:

Answer:lossed

Explanation:

When halogens react with metals,they form salts called metal halides according to their electronic configuration according to which reaction takes place.

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.

Learn more about electronic configuration,here:

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Answer:

D: When the acidity of a solution increases, the pH increases.

Explanation:

It is totally wrong to assert that when the acidity of a solution increases, the pH of the solution will increase

The right answer is that when the acidity of a solution increases, the pH value decreases.

Answer:

See below:

Explanation:

The grasshopper doesn't require an exchange of gasses (air) using a circulatory system because the gasses directly reach its cell's from the "air sacs" which spread out into tiny tubes close to each cell.

Answer:

3.8 x 10²⁴molecules

Explanation:

Given parameters:

Number of moles  = 6.32moles

Unknown:

Number of molecules  = ?

Solution:

The number of moles can be used to derive the number of molecules found within a substance.

Now,

       1 mole of substance contains 6.02 x 10²³ molecules

     6.32 mole of PBr₃ will contain 6.32 x 6.02 x 10²³ = 3.8 x 10²⁴molecules

Answer:Boiling point of a solution is found to be 100.34  

o

C. Boiling point of pure

water is 100  

o

C.      

The elevation in the boiling point ΔT  

b

​  

=100.34−100=0.34  

o

C.

12 gm glucose (molecular weight 180 g/mol) is dissolved in 100 gm water.

The number of moles of  glucose =  

180g/mol

12g

​  

=0.0667mol

Mass of water =100g×  

1000g

1kg

​  

=0.100kg

Molality of solution m=  

0.100kg

0.0667mol

​  

=0.667mol/kg

The elevation in the boiling point ΔT  

b

​  

=K  

b

​  

×m

0.34  

o

C=K  

b

​  

×0.667mol/kg

K  

b

​  

=0.51  

o

Ckg/mol

The molal elevation constant for water is 0.51  

o

Ckg/mol.

Explanation:

Answer:

1.) 12 tablespoons of sugar and 3 cups of water (48 tablespoons)

2.) Amount of lemon juice, sugar and water required will be = 0.375 cups, 0.75 cups and 3 cups.

Step-by-step explanation:

Malanie is making lemonade and finds a recipe that requires lemon juice, sugar and water in the ratio of 1 : 2 : 8.

She juices 2 lemons to obtain 6 tablespoons of lemon juice.

∵ 16 tablespoons = 1 cup

∴ 1 tablespoon =  cup

∴ 6 tablespoon =   cup =  0.375 cups

Since ratio between lemon and sugar is 1 : 2

So amount of sugar required = 0.375×2 = 0.75 cups

Ratio between lemon and water is 1 : 8

So amount of water required = 0.375×8 = 3 cups

Therefore, amount of lemon juice, sugar and water required = 0.375 cups, 0.75 cups sugar and 3 cups respectively.

Explanation:

Answer:

18 cups.

Lemon Juice

I put 4.5 cups of sugar

I got 4/5 on this quiz and I don't remember which was wrong but there you go...

Answer:

B. Respiratory System

Answer:

B, Respiratory

Explanation: