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3 years ago

What are the elements in the first period

Chemistry

2 answers:

aliina [53]3 years ago

6 0

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

Bond [772]3 years ago

6 0

Answer:

"Hydrogen and Helium". Hydrogen and Helium are the elements of the first period in the modern periodic table.

Explanation:

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What has the lowest ionization erergy?

Svetach [21]

Answer:

Francium (Fr)

Explanation:

From the given choices, francium will have the lowest ionization energy.

Ionization energy is the energy required to remove the most loosely held electron within an atom.

The magnitude of the ionization energy depends on the characteristics of the atom in relation to its nuclear charge, atomic radius, stability etc.

Generally on the periodic table, ionization energy increases from left to right on the table
As you go from metals to non-metals and to gases, the value of the ionization energy increases steadily.
Down the group, the value reduces.
Since Francium is the most metallic of all the given choices, it has the highest ionization energy.

3 0

3 years ago

Give the name and formula of the compound formed from the following elements: (a) sodium and nitrogen; (b) oxygen and strontium;

lisov135 [29]

Answer:

For a: The chemical name and chemical formula formed is sodium nitride and $Na_3N$

For b: The chemical name and chemical formula formed is strontium oxide and $SrO$

For c: The chemical name and chemical formula formed is aluminium chloride and $AlCl_3$

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

The nomenclature of ionic compounds is given by:

1. Positive is written first.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

For a: Sodium and nitrogen:

Sodium is the 11th element of periodic table having electronic configuration of $[Ne]3s^1$

To form $Na^{+}$ 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.

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 sodium nitride is $Na_3N$

For b: Oxygen and strontium

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.

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 strontium oxide is $SrO$

For c: Aluminium and chlorine

Aluminium is the 13th element of periodic table having electronic configuration of $[Ne]3s^23p^1$

To form $Al^{3+}$ ion, this element will loose 3 electrons.

Chlorine is the 17th element of the periodic table having electronic configuration of $[Ne]3s^23p^5$

To form $Cl^{-}$ ion, this element will gain 1 electron.

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 aluminium chloride is $AlCl_3$

4 0

3 years ago

how does the percentage by mass of the solute describe the concentration of an aqueous solution os potassium sulfate

kirza4 [7]

Answer:

Explanation:

In an aqueous solution of potassium sulfate (K₂SO₄), the solute is K₂SO₄ and the solvent is water. The percentage by mass describes the grams of solute there are dissolved per 100 grams of solution. It can be calculated as:

mass percentage = (mass of solute/total mass of solution) x 100%

For example, in an aqueous solution which is 2% by mass of K₂SO₄, there are 2 grams of K₂SO₄ per 100 g of solution.

3 0

2 years ago

Thomas collected the data in Table 1 to answer a statistical question. Which statistical question does the data in Table 1 answe

Nezavi [6.7K]

Answer:

how tall each sibling is

Explanation:

6 0

3 years ago

Read 2 more answers

How many electrons are in the highest occupied energy level of these atoms?

Yuliya22 [10]

Excuse me not giving an explanation; I haven't even learned chemistry before. I usually give explanations for math/english.

I think it would be for flourine: 7
aluminum: 8
can't help with the rest...
sorry!

8 0

3 years ago