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3 years ago

Helpppppppppppppp please

Chemistry

1 answer:

Mama L [17]3 years ago

4 0

1)
-Lithium: Lithium got 3 protons, so it atomic number is 3. It is located on the first column of the periodic table, and belonging to the alkali metal. So lithium is a metal. Lithium is highly reactive.
-Neon: It is located on the 18th column of the periodic table, and belong to the noble gases. So Neon is a nonmetal. Neon's reactivity is very low.
-Fluorine: Located on the 17th column of the periodic metal, fluorine is a nonmetal, and belong to the halogen family. Fluorine's reactivity is high.

2)
-Vertical columns of the periodic table are called columns. There is 18 column in the periodic table, and each one represent a chemical family.
-Horizontal rows of the periodic table care called periods. There is 7 periods in the periodic table.
-The number of protons in an atom is that element's atomic number. And since the atom is electrically neutral, the number of protons is equal to the number of electrons. So if you have the number of electrons, you can still find the atomic number.
-The total of protons and neutrons in an atom is that element's atomic mass. Based on the formula A = Z + N, where A represents the atomic mass, Z the atomic number (number of protons) and N the number of neutrons.
-The elements in group 1 are the most reactive metals. This group is called the Alkali metals. They only have 1 electron in their outer shell which makes them always ready to lose an electron in an ionic bonding.
-The elements in group 17 are the most reactive nonmetals. This group is called the Halogens, with 7 electrons in their outer shell which makes them always ready to win an electron in an ionic bonding.
-The elements in group 18 are the most unreactive elements. This group is called the Noble gases. Their outer shell is always full, so it can't do reactions.

Hope this Helps! :)

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Hyposulfite, SO22–, is a polyatomic ion that has not yet been definitively confirmed to exist. However, the VSEPR model may stil

LUCKY_DIMON [66]

Answer:

The most reasonable estimate for the O–S–O bond angle in hyposulfite = 106°

Explanation:

Hyposulphite (so₂²⁻) is polyatomic ion .

According to VSEPR model

Total elrctron pairs $=\frac{1}{2} [V+X -C+A]$

V = Valence shell electrons of central element

X = No. of monovalent surrounding atoms

C = Cationic charge

A = Anionic charge

Total electron pairs $=\frac{1}{2}[6+0-0+2]= 4$

That is two bond pairs and two lone pairs

6 0

3 years ago

6. Find the partial pressures of the gases in a mixture with a total pressure of 101.3 kPa, if there are 7.8 mole of

ikadub [295]

Answer:

Explanation:

Total mole of gases = 7.8 + 2.1 + .09 + .01 = 10

the partial pressures of the gases in a mixture

= mole fraction x Total pressure

mole fraction = mole of a gas in the mixture / total mole

partial pressure of Ng = $\frac{7.8}{10} \times 101.3 kPa$

= 79.014 kPa

partial pressure of O = $\frac{2.1}{10} \times 101.3 kPa$

= 21.273 kPa .

partial pressure of Ar = $\frac{.09}{10} \times 101.3 kPa$

= .9117 kPa .

partial pressure of Co = $\frac{.01}{10} \times 101.3 kPa$

= .1013 k Pa .

3 0

3 years ago

What is the total number of atoms present in 5Na,PO.?

denis23 [38]

Answer:

3.01×10²⁴ atoms

Explanation:

Our compound is the Na₃PO₄

Sodium phosphate.

We assume, we have 5 moles of the mentioned salt.

1 mol of anything contains 6.02×10²³ atoms.

That's the Avogadro's number. The conversion is:

5 mol . 6.02×10²³ atoms /1mol = 3.01×10²⁴ atoms

6 0

3 years ago

Balance the chemical equation given below, and determine the number of grams of MgO that are needed to produce 20.0 g of Fe2O3.

Alenkasestr [34]

Answer:

1.) The balanced equation is 3MgO(s) + 2Fe(s) ===> Fe2O3(s) + 3Mg(s)

2.) 20g of Fe2O3 will be produced by 20 ×120/160 = 15g of MgO

Explanation:

THE CORRECT EQUATION IS: MgO(s) + ___ Fe(s) ===> Fe2O3(s) + ___ Mg(s)

The balanced equation is: 3MgO(s) + 2Fe(s) ===> Fe2O3(s) + 3Mg(s)

molar mass of 3MgO = 3(24 + 16) = 120

Molar mass of Fe2O3 = 2 X 56 + 3 X 16

=112 +48 =160

From the equation, 120g of MgO Produced 160g of Fe2O3

Therefore 20g of Fe2O3 will be produced by 20 ×120/160 = 15g of MgO.

7 0

3 years ago

Which of the following species contains manganese with the highest oxidation number?

ioda

In NaMnO₄, Mn has the highest oxidation number.

The question is incomplete, the complete question is;

Which of the following species contains manganese with the highest oxidation number?

A) Mn

B) MnF₂

C) Mn₃(PO₄)₂

D) MnCl₄

E) NaMnO₄

In order to ascertain the specie that contains manganese with the highest oxidation number, we must calculate the oxidation number of manganese in each of the species one after the other.

1) For Mn, the oxidation number of Mn is zero because the atom is uncombined.

2) For MnF₂;

Mn has an oxidation number of +2

3) For Mn₃(PO₄)₂

Mn has an oxidation number of +2

4) For MnCl₄

Mn has an oxidation number of +4

5) For NaMnO₄

Mn has an oxidation number of +7

Hence in NaMnO₄, Mn has the highest oxidation number.

Learn more: brainly.com/question/10079361

7 0

3 years ago