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3 years ago

Why is the table of elements called the periodic table?

Chemistry

2 answers:

Vsevolod [243]3 years ago

6 0

Answer:

I'm not sure which one is correct but I hope my explanation helps.

Explanation:

It is called the periodic table because of the way the elements are arranged. You'll notice they're in rows and columns. The horizontal rows (which go from left to right) are called 'periods' and the vertical columns (going from up to down) are called 'groups'

V125BC [204]3 years ago

4 0

It is in the d or b

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I’ll mark you brainley if you help me figure out which answer it is!!!

Stolb23 [73]

Answer:

Explanation:

A chemical change happens when one chemical substance is transformed into one or more different things , such as when iron becomes rust so

B: Acids turn the indicator red, pink, orange, and yellow, while bases turn it green based on what it reactions with or comes in contact with so b is maybe

c is wrong

and d a physical change, will technically yes and no there should have not been a smell afterwards so the only really choose that makes sense here is A

5 0

3 years ago

Which electrons are the valence electrons of the atom? Helpppppppp

Arlecino [84]

Explanation:

electrons in the highest energy orbitals which are able to contribute to Bonding are valence electrons,....... please mark me brainiest

4 0

3 years ago

1. How does protein substance in animal hide or skin be preserved from bacterial infection during tanning?

anyanavicka [17]

Answer:

1. By being cured

2. To remove the silica impurities from haemetite

3. The cathode will be bronze while the anode will be the silver

4. i) Wastes from industrial processes

ii) Waste waters and sewage

iii) Dumping of wastes into water bodies

5) Three methods to reduce air pollution includes

i) Promote the use of recycled of materials

ii) Promote and use renewable sources of energy

iii) Limit activities that involve the burning of fuels such as encouraging the use of mass transit buses, preventing the occurrence of fires in forests

Explanation:

1. In order to preserve the proteins in the hides of animal skin from putrefaction they are cured with salt to remove by, osmotic pressure difference, the water content present in the animal hide

2. To remove the silica impurities from haemetite

The calcium oxide obtained from the decomposition of calcium carbonate undergoes a chemical reaction with the sand impurities in the mineral, haematite, to form calcium silicate or s l a g

3. Electroplating involves charging the metal to be electroplated negatively that is making it the cathode and placing it in an electrolytic cell that has a solution of the metal ions containing the metal salts

Therefore, the bronze medal to be plated with silver will be made the cathode while the silver from which we obtain the silver ions will be made the anode

4. Three causes of water pollution includes

Wastes from industrial processes

Waste waters and sewage

Dumping of wastes into water bodies

5. The major causes of air pollution are the oxides produced from the combustion of fossil fuels such as sulfur dioxide, carbon dioxide, carbon monoxide as well as chemical gases from industrial processes.

8 0

3 years ago

TIMED TEST!!

LuckyWell [14K]

The number 7 is the coefficient

5 0

4 years ago

Read 2 more answers

Give the formulas of the compounds in each set (a) lead(l|) oxide and lead(lV) oxide; (b) lithium nitride, lithium nitrite, and

Ivanshal [37]

Answer:

For a: The formula of lead (II) oxide and lead (IV) oxide is $PbO\text{ and }PbO_2$ respectively.

For b: The formula of lithium nitride, lithium nitrite and lithium nitrate is $Li_3N,LiNO_2\text{ and }LiNO_3$ respectively.

For c: The formula of Strontium hydride and strontium hydroxide is $SrH_2\text{ and }Sr(OH)_2$ respectively.

For d: The formula of magnesium oxide and manganese (II) oxide is $MgO\text{ and }MnO$ respectively.

Explanation:

All the given compounds are ionic compounds. This means that between the atoms complete sharing of electrons takes place.

For a:

Lead is the 82th element of periodic table having electronic configuration of $[Xe]4f^{14}5d^{10}6s^26p^2$ .

To form $Pb^{2+}$ ion, this element will loose 2 electrons and to form $Pb^{4+}$ ion, this element will loose 4 electrons.

Oxygen is the 8th element of periodic table having electronic configuration of $[He]2s^22p^4$ .

To form $O^{2-}$ ion, this element will gain 2 electrons.

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

So, the chemical formula for lead (II) oxide is PbO and for lead (IV) oxide is $PbO_2$

Thus, the formula of lead (II) oxide and lead (IV) oxide is $PbO\text{ and }PbO_2$ respectively.

For b:

Lithium is the 3rd element of periodic table having electronic configuration of $[He]2s^1$ .

To form $Li^{+}$ ion, this element will loose 1 electron.

Nitrogen is the 7th element of periodic table having electronic configuration of $[He]2s^22p^3$ .

To form $N^{3-}$ ion, this element will gain 3 electrons.

Nitrite ion is a polyatomic ion having chemical formula of $NO_2^{-}$

Nitrate ion is a polyatomic ion having chemical formula of $NO_3^{-}$

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

So, the chemical formula for lithium nitride is $Li_3N$ , for lithium nitrite is $LiNO_2$ and for lithium nitrate is $LiNO_3$

Thus, the formula of lithium nitride, lithium nitrite and lithium nitrate is $Li_3N,LiNO_2\text{ and }LiNO_3$ respectively.

For c:

Strontium is the 38th element of periodic table having electronic configuration of $[Kr]5s^2$ .

To form $Sr^{2+}$ ion, this element will loose 2 electrons.

Hydrogen is the 1st element of periodic table having electronic configuration of $1s^1$ .

To form $H^{-}$ ion, this element will gain 1 electron and is named as hydride ion.

Hydroxide ion is a polyatomic ion having chemical formula of $OH^{-}$

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

So, the chemical formula for strontium hydride is $SrH_2$ and for strontium hydroxide is $Sr(OH)_2$

Thus, the formula of Strontium hydride and strontium hydroxide is $SrH_2\text{ and }Sr(OH)_2$ respectively.

For d:

Magnesium is the 12th element of periodic table having electronic configuration of $[Ne]3s^2$ .

To form $Mg^{2+}$ ion, this element will loose 2 electrons.

Manganese is the 25th element of the periodic table having electronic configuration of $[Ar]3d^54s^2$

To form $Mn^{2+}$ ion, this element will loose 2 electrons.

Oxygen is the 8th element of periodic table having electronic configuration of $[He]2s^22p^4$ .

To form $O^{2-}$ ion, this element will gain 2 electrons.

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

So, the chemical formula for magnesium oxide is MgO and for manganese (II) oxide is MnO.

Thus, the formula of magnesium oxide and manganese (II) oxide is $MgO\text{ and }MnO$ respectively.

7 0

3 years ago