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

Answers

Answer 1

Answer:

they are in group II and they have two electrons in their outermost energy levels ( valency)...is this helpful?


Related Questions

Desperate Please Hurry
What was the evidence that Earth was round before there were photos from space?

Answers

Answer:

Explanation:

Are there any awnser choices?

Many believed that since the moon and sun were a circle or round shape they believed that’s also how the earth was shaped. Hope this can help!

A sample of gas occupies 20 mL at -109 degree C. What volume does the sample
occupy at 65 °C?

Answers

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

what are isotopes and explain why​

Answers

Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element's atomic number on the Periodic Table. For example, carbon has six protons and is atomic number 6.

what is the difference between nitrite and nitrate​

Answers

Answer:

Nitrite:

Formula : NO₂⁻1 nitrogen molecule and two oxygen molecules with an excess electron.Angular shape

Nitrate:

Formula: NO₃⁻1 nitrogen molecule and three oxygen molecules with an excess electron.Trigonal planar structure.

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

Hope this helped!

~AH1807

When you take a hot shower, the
a
shower curtain sometimes moves
into the shower towards you. Why
does this happen?

Answers

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

Explain how wind and water can create a sand dune along an ocean beach

Answers

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.

Answers..,.ًًًًًًًًًًًًًًًًًًًًًًًًًًًًً………..,.,.,…,.,.,.,

Answers

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

Two protons and two neutrons are released as a result of this reaction. Superscript 222 subscript 86. Rn Right arrow superscript 218 subscript 84. Po ? Which particle is released? one alpha particle two beta particles one alpha and one beta particle one high-energy photon.

Answers

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:

what describes the pool of electrons in metallic bonding?

Answers

In metallic bonding, the electrons are “surrendered” to a common pool and become shared by all the atoms in the solid metal. Metallic bonding is found in metals and their alloys. When the atoms give up their valence electrons, they form ions. These ions are held together by the electron cloud surrounding them.

How many molecules are in 10 grams of sulfur hexafluoride (SF6)? Molar Mass: 146.06 g/mol​

Answers

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.

helllloooook this makes no sense help me plz

Answers

may i ask?

How do you use this app?

1. what property of gas does not change?

2. Name two gases besides oxygen found in Earth's atmosphere

Answers

Answer:

hydrogen and nitrogen or something?

Explanation:

Answer:

nitrogin and i forgot the other one srry!!

Explanation:

Which statement is correct about charges?
A.Opposite charges repel
B.Similar charges attract
C.Electrons are positively charged
D.Similar charges repel

Answers

Answer:

A.Opposite charges repel

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

D.Similar charges repel

correct me if I'm wrong

hope it helps

One of the main properties used to describe a population

Answers

Answer:

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

Explanation:

What do these red/yellow/orange-precipitate reactions have in common? (choose
the best answer)

They all made the same color.

They all have a barium (Ba+2) cation.

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


They all have a chloride ( C1-1) ion.

Answers

Answer:

3 is the correct I think so

Answer:

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

Explanation:

Crumpling and tearing cause physical changes to a piece of paper.
Which two characteristics of the paper change?
A. Size
B. Reactivity
I C. Identity
I D. Shape


Please help I’ll give brainlist and no spamming or links just please help

Answers

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

How many molecules are in 1.3 moles of water?​

Answers

Answer:

7.8286e+23

Explanation:

Use Avogadro's number

Pls some one help
1 mark question

Answers

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!

~AH1807

Which animal is found in the desert?

monkeys

parrots

buffalo

meerkats

Answers

Answer:

meerkats

Explanation:

A student is asked to describe three random
elements found on the periodic table. All three
elements will FOR SURE have which of the two
following characteristics?
A. similar color and texture
B. shininess and value
C. mass and volume
D. similar boiling and freezing points

Answers

C hope u get it right bye

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

What is an element?

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:

https://brainly.com/question/14347616

#SPJ2

What is x?





a
28
b
44
c
224
d
136

Answers

Answer:

Hope answer is right, d=136


Ores contain enough metal to make extraction of the metal ______
economical.
reversible.
carbon neutral.

Answers

Answer:

oxide

Explanation:

How to get rid of high cholesterol?!




Please tell me

Answers

you have to drink a lot of water and 67890

A horticulturalist wants to produce geraniums with specific characteristics.

She knows that the trait of red flowers is governed by the allele R (RR and Rr) and the trait of white flowers is governed by the allele r(rr).

The horticulturalist crosses two geraniums from the F1 generation.

Look at the Punnett square to see this cross.

R r
R RR Rr
r Rr rr


Which ratio of red-to-white flowering plants would she expect to see in the phenotypes of the F2 generation?

all red

3 red : 1 white

1 red : 3 white

2 red : 2 white

Answers

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

True/False: For the same system, heterogeneous nucleation will occur at less undercooling than homogeneous nucleation.

Answers

Answer:

True.Explanation:

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

Which of the following is true for a nuclear reaction?
O Electrons are lost
Electrons are gained
O Identity of element changes
Oldentity of element remains same

Answers

Identity of element changes.

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

What are nuclear reactions?

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

As it is said that changes are taking place in nucleus so the electrons are not gained or lost in this reactions.Identity of the element changes as atomic number of element changes due to change in the number of protons.

Hence identity of element changes.

To know more about nuclear reactions, visit the below link:
https://brainly.com/question/984564

How do characteristic properties help you determine whether a chemical
change or a physical change has occurred? I

Answers

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:

How do you prepare 500ml of 1.77M H2SO4 solution from an 18.0M H2SO4 Stock solution

Answers

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

Help me please…………..d

Answers

This is a double replacement reaction

pls some one help
1 mark question

Answers

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!

~AH1807
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