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4 years ago

How many electrons does the predictable (most common) ion of calcium contain?

1 answer:

3 0

Answer: 18

Justification:

1) The most common ion of calcium is Ca 2+

2) That means that the atom, neutral calcium, has lost two electrons.

3) The atomic number of calcium is 20.

4) Atomic number is the number of protons, so calcium has 20 protons.

5) Therefore, the neutral atom of calcium also has 20 electrons (to make a net charge of zero).

6) Then, the ion Ca 2+ has 20 - 2 = 18 electrons.

Answer: 18 electrons.

You might be interested in

What masses of sodium chloride, magnesium chloride, sodium sulfate, calcium chloride, potassium chloride, and sodium bicarbonate

andreyandreev [35.5K]

Answer:

NaCl: 184g

MgCl₂: 6.60g

Na₂SO₄: 9.26g

CaCl₂: 1.28g

KCl: 0.70g

NaHCO₃: 0.13g

Explanation:

To convert these concentrations to masses we need to convert molarity to moles and moles to grams using molar mass of each salt:

[CaCl₂] = [Ca²⁺] = 0.0115M

[HCO₃⁻] = [NaHCO₃] = 0.0015M

[SO₄²⁻] = [Na₂SO₄] = 0.0652M

[Mg²⁺] = [MgCl₂] = 0.0693M

[K⁺] = [KCl] = 0.0094M

And using the concentration of Cl⁻:

[Cl⁻] = [NaCl] + 2[MgCl₂] + 2[CaCl₂] + [KCl]

[3.32] = [NaCl] + 2[0.0693] + 2[0.0115] + [0.0094]

[NaCl] = 3.149M

The masses you need are:

<em>NaCl (Molar mass: 58.44g/mol):</em>

3.149mol/L * 1L * (58.44g/mol) =

<em>MgCl₂ (Molar mass: 95.211g/mol):</em>

0.0693mol/L * 1L * (95.211g/mol) =

Na₂SO₄<em> (Molar mass: 142.04g/mol):</em>

0.0652mol/L * 1L * (142.04g/mol) =

CaCl₂<em> (Molar mass: 110.98g/mol):</em>

0.0115mol/L * 1L * (110.98g/mol) =

KCl<em> (Molar mass: 74.55g/mol):</em>

0.0094mol/L * 1L * (74.55g/mol) =

<em>NaHCO₃ (Molar mass: 84g/mol):</em>

0.0015mol/L * 1L * (84g/mol) =

<h3>0.13g NaHCO₃</h3>

7 0

3 years ago

I need help, I don't understand the question

rjkz [21]

The awnser is probably B

7 0

3 years ago

What type of reaction will occur with the following reactants?

zalisa [80]

Answer:

A) double replacement

Explanation:

Chemical equation:

NaCl +CaS → Na₂S + CaCl₂

Balanced chemical equation:

2NaCl +CaS → Na₂S + CaCl₂

The given reaction is double replacement reaction in which cation and anions of each reactant exchange with each other.

Double replacement:

It is the reaction in which two compound exchange their ions and form new compounds.

AB + CD → AD +CB

Other options are incorrect because,

Synthesis reaction:

It is the reaction in which two or more simple substance react to give one or more complex product.

AB → A + B

Single replacement:

It is the reaction in which one elements replace the other element in compound.

AB + C → AC + B

Decomposition reaction:

It is the reaction in which one reactant is break down into two or more product.

AB → A + B

6 0

3 years ago

How to deal with a broken thermometer in chemistry lab ?

svetlana [45]

Isolate the lab immediately mercury can be easily tracked throughout a lab by people walking on spill. laboratory staff can safely clean up small spill . don't stamp on small pieces . carefully inspect the bench tops and floors before sitting. to avoid hurting .

3 0

3 years ago

After mixing the solutions in a separatory funnel, the stopper should be ______ and the liquid should be _______ and the layers

maw [93]

Answer:

Hence,

1) removed

2) drained through the stopcock

3) get eye level with

4) slow the draining

5) switch to a new flask

Explanation:

After mixing the solutions in a separatory funnel, the stopper should be removed and the liquid should be drained through the stopcock, and the layers allowed to separate. When you get close to the interface between the layers, get eye level with the funnel and turn over to slow the draining heat up until the first layer is collected. Switch to a new flask get eye level with it to collect the second layer.

7 0

3 years ago