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Nesterboy [21]
3 years ago
13

What is true about the element calcium(Ca, atomic number 20)? Choose all that apply.

Chemistry
2 answers:
Marat540 [252]3 years ago
7 0
It has 2 valence electrons

THANK ME
Shkiper50 [21]3 years ago
5 0

Answer:

It has 2 valence electrons

It is a metal.

Explanation:

Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal.

In chemistry, a metal is an element that readily forms positive ions (cations) by losing electrons.

Calcium belongs to group 2 and would give up it's two valence electrons in reactions.

The electronic configuration is given as;

Ca : 1s2 2s2 2p6 3s2 3p6 4s2 or [Ar] 4s²

Valence electron represents the outermost electrons.

The correct options are;

It has 2 valence electrons

It is a metal.

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How would you separate copper sulfate crystals from its solution?​
tia_tia [17]

Answer: You would separate it by dissolving them.

4 0
3 years ago
Why are relative atomic masses on the periodic tables not whole numbers?
Kobotan [32]

Answer:

They are averages.

Explanation:

atomic numbers on periodic tables are derived from the average value of all the isotopes of the element. So being averages they are sometimes not integers.

6 0
3 years ago
Read 2 more answers
Question 4(Multiple Choice Worth 4 points)
vitfil [10]

Answer:

The quantum number that describes the orientation of an orbital within a sublevel is the magnetic quantum number.

Explanation:

There are four quantum numbers in chemistry. These are the principal quantum number, the angular momentum quantum number, the magnetic quantum number, and the spin quantum number. These all follow these three foundational rules in chemistry.

The Pauli exclusion principle states that if two electrons inhabit the same orbital, they will spin in different directions.

Hund's rule states that if an orbital does not have an electron, an electron will need to fill it first before any of the other orbitals can have two electrons of differing spins.

The Aufbau principle states that all electrons will fill orbitals in an orderly fashion based on the quantum numbers.  An attachment is included of this fill order for your reference.

The four quantum numbers for chemistry are:

The principal quantum number describes the sublevel in which the orbital is located. This occurs at n = 1, 2, 3, etc. all the way to 7.

The angular momentum quantum number describes the orbital that an electron fills. It will refer to the shape and the type of orbital.  

The magnetic quantum number refers to the orientation of an orbital. Based on the angular momentum quantum number, there can be 1, 3, 5, or 7 orientations.

The spin quantum number refers to the Pauli exclusion principle. This number is assigned a negative or positive based on the orientation of the electron.

Therefore, because the magnetic quantum number is the one that refers to <u>the orientation of the orbital</u>, this is our answer.

5 0
3 years ago
PLZ HELP I WILL GIVE U BRAINLEST PLZ HELP!!!!!!!!!!
sergeinik [125]
My answer is A. I'm probably wrong. in bad in this subject
7 0
3 years ago
Read 2 more answers
A saturated solution of manganese(II) hydroxide was prepared, and an acid–base titration was performed to determine its KspKsp a
trapecia [35]

Answer:

10.945 x 10^-4

Explanation:

Balanced equation:

Mn(OH)2 +  2 HCl  -->  MnCl2  +  H2O

it takes 2 moles HCL for each mole Mn(OH)2

Next find the molarity of the Mn(OH)2 solution

= (1 mole Mn(OH)2 / 2 mole HCl)  X (0.0020 mole HCl / 1000ml) X (4.86 ml)    

= 4.86 x 10^-3 mole  

this is now dissolved in (70 + 4.86)  =  74.86 ml or 0.07486 L

thus [Mn(OH)2]  =  4.86 x 10^-3 mole / 0.07486 L  =  0.064921 M

Ksp =  [Mn2+][OH-]^2  =  4x^3  =  4(0.064921)^3  = 10.945 x 10^-4

6 0
3 years ago
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