2. Write down the position of alkaline earth metal in the Modern periodic table What is their valency? ​

Answer:

See below

Explanation:

Helium belongs to group VIII of the periodic table "Noble gases". It has only 1 electronic shell and that too contains 2 electrons according to the accommodation of the shell. Hence, it's electronic shell is complete. This is the reason, Helium is chemically unreactive.

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

True.Explanation:

same system, heterogeneous nucleation will occur at less undercooling than homogeneous nucleation.

Answer: The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.

Explanation:

you have to drink a lot of water and 67890

Answer:

[tex] \: \: \: \: [/tex]

correct me if I'm wrong

Answer:

Birth rate, death rate, emigration, immigration, or a census.

Explanation:

Answer:

7.8286e+23

Explanation:

Use Avogadro's number

Answer:

Explanation:

Are there any awnser choices?

Answer:

Take 49.2-ml of 18.0 M H2SO4 stock solution and pour it into a 500-ml volumetric flask. Fill to the 500-ml line with distilled water to make 1.77M H2SO4 solution.

Explanation:

use the formula M1V1=M2V2

volume must be in liters(L)

[tex](1.77)(500 \times {10}^{ - 3} ) = (18)v2 \\ 0.885 = 18v2 \\ v2 = \frac{0.885}{18} \\ v2 = 0.04916[/tex]

0.04916L × 1000 = 49.16 ml = 49.2 ml

Answer:

meerkats

Explanation:

size and shape. only the appearance of the paper will have changed, but is reversible.

All three elements  in the periodic table will for sure have characteristic of mass and volume.

An element  is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom which is characteristic of it's own. Due to this reason all elements are different from one another.

Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.

The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.

Learn more about element,here:

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Answer:

3 is the correct I think so

Answer:

They all have a chromate (CrO4-2) ion.

Explanation:

Answer:

1) actual yield - 2.675 g

Theoretical yield - 4.0539 g

2)a) 41.257 g

b) 0.6857moles

c) 23 g

Explanation:

1)

Theoretical yield is the mass of the product that can obtain from the equation, it is not practical.

Theoretical yield:

Mr of SiO2 - 60

Moles of SiO2 - 2.339/60 = 0.03898 moles

Mr of SiF4 - 104

Mass of SiF4 - 0.03898 * 104 = 4.05392 g

2)

a)

mr of B2H6 - 28

Moles of B2H6 - 36.1/28 = 1.2893 moles

Mr of O2 - 32

Mass of O2 - 32 * 1.2893 = 41.257 g

b)

Moles of B2H6 - 19.2/28 = 0.6857 moles

Stoichiometry 1:1 ratio between B2H6 and H2O

So moles of H2O is 0.6857

c) moles of O2 - 2/24(r.t.p) = 0.083 moles

Mass of B2H6 - 0.083 * 28 = 2.3 g

Answer: V2= 41.2mL

Explanation:

Givens:

* V1= 20ml

* T1 = -109 ⁰C --> K= ⁰C + 273.15 --> 164.15 K

* V2 = ??

* T2= 338.15 K

Use Charles law V1/T1 = V2/T2

Since we are looking for V2 we can rearrange the formula to

V2= (T2 x V1) /T1

V2= (338.15K x 20mL) / 164.15 K

V2= 41.2mL

NOTE:

Temperature should always be in K not in ⁰C or ⁰F

To convert from C to K use

*K= ⁰C + 273.15

Enter your C value in the ( ⁰C ) and you can get K

With hot water comes hot steam, it fills the shower area with steam which raises the air temperature and the air then rises out of the shower

Answer: 4.123 x 10^22

Explanation:

The first step is to determine how many moles of sulfur hexafluoride (SF6) there are. To do this, you must take the mass of the SF6 (10g) and divide it by the molar mass (146.06).

[tex]10g * \frac{1 mol}{146.06 g}= 0.068465 mol[/tex]

Then you must use Avagadros number to find the number of molecules.

Avagadros number is the number of molecules in 1 mol of a substance, so a simple multiplication will do the trick.

[tex]0.068465mol * \frac{6.022 * 10^{23}}{1mol} = 4.123*10^{22}[/tex]

And that is your answer. There are 4.123 x 10^22 molecules of sulfur hexafluoride in 10g of it.

Answer:

oxide

Explanation:

Answer: A dune is a mound of sand formed by the wind, usually along the beach or in a desert.  Dunes can also be formed by strong currents beneath the water.

Yo,

In Geranium plant life red vegetation is given by using the allele R this is dominant (so RR or Rr ) genotype will produce crimson plant life.

If we communicate approximately the connected punnet square which i took from the workout e book, you could see that there was a cross made among vegetation with heterozygous genotype for red flora.

P1: Rr X Rr

Gametes: R: r : R : r

F1: RR: Rr: Rr: rr

so there is three: 1 in F1 offspring for red to white plant life.

Now the query is set f2 technology, while we cross F1 generation suppose we do a move of Rr and rr from F1 generations allow us to see what takes place.

F1: Rr: rr

Gametes: R: r: r: R

F2 : Rr : rr: Rr: rr

Rr: purple flowers

rr: White flora:

So the ratio in F2 era might be 2 crimson : 2 white. Please see connected punnet squares (first one for query) and the second of F1 move for better know-how.

I'm hoping that this will benefit you, so from my assumption and study it'd be 2 crimson : 2 white, if this is indeed the one i'm thinking of since nothing else was provided, if not please correct me.

Answer: 2 red : 2 white

Explanation:

I know

The particle released in the reaction has been an alpha particle. Thus, option A is correct.

The release of protons and neutrons in a reaction has been nuclear reactions. The reactions results in the change in the atomic mass of the atom, with the formation of new atom. The extra mass has been released in the form of energy.

The release from the given reaction has been:

[tex]\rm ^{222}_{66}Rn\;\rightarrow\;^{218}_{84}Po\;+\;^A_ZX[/tex]

Where, X has been the particles that has been released with the nuclear reaction. The superscript A has been the Mass of particle, and subscript Z has been the atomic number.

According to the law of conservation, the mass has been constant on both the product and the reactant side. Thus, the mass and atomic number of eliminated particles has been given as:

[tex]\rm 222=218+A\\A=222-218\\A=4[/tex]

The atomic mass of the particle has been 4.

[tex]\rm 86=84+Z\\Z=86-84\\Z=2[/tex]

The atomic number of the particle has been 2.

The element with atomic mass 4, and atomic number 2 has been the Helium particles, [tex]\rm ^4_2He[/tex]. It has been an alpha particle. Thus, the particle released in the reaction has been an alpha particle. Thus, option A is correct.

For more information about the particles released, refer to the link:

https://brainly.com/question/2600896

Answer:

A

Explanation:

may i ask?

How do you use this app?

True statement for a nuclear reactions is that it changes the identity of the element.

Nuclear reactions are those reactions in which changes in the nucleus of atoms take place in the form of fission and fussion.

Hence identity of element changes.

To know more about nuclear reactions, visit the below link:
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Answer:

hydrogen and nitrogen or something?

Explanation:

Answer:

nitrogin and i forgot the other one srry!!

Explanation:

Answer:

The atomic number of Chlorine(Cl) is 17 and the electronic configuration is 2,8,7 with seven electrons in the valence shell.

Hope that helps. x

Answer:

See below

Explanation:

Chlorine has 17 electrons in it's shell.

(See the attached file to get the idea of what subshell would be filled first).

The accommodations:

s = 2 electrons

p = 6 electrons

d = 10 electrons

f = 14 electrons

Now, the electronic configuration of chlorine:

1s²2s²2p⁶3s²3p⁵

(2+2+6+2+5 = 17 electrons)

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Hope answer is right, d=136

Answer:

Nitrite:

Nitrate:

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Hope this helped!