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2 years ago

How does the periodic table indicate the number of valence electrons element has?

Chemistry

1 answer:

Yuri [45]2 years ago

7 0

option A.

The number of valence electrons of an element can be determined by the periodic table group (vertical column) in which the element is categorized

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Gallium oxide, Ga.Oy, forms when gallium is combined with oxygen. A 1.25 g of Ga is allowed to react with excess oxygen and 1.68

mrs_skeptik [129]

Answer : The chemical formula of a compound is, $Ga_2O_3$

Solution : Given,

Mass of gallium = 1.25 g

Mass of gallium oxide = 1.68 g

Mass of oxygen = Mass of gallium oxide - Mass of gallium

Mass of oxygen = 1.68 - 1.25 = 0.43 g

Molar mass of Ga = 69.72 g/mole

Molar mass of O = 16 g/mole

Step 1 : convert given masses into moles.

Moles of Ga = $\frac{\text{ given mass of Ga}}{\text{ molar mass of Ga}}= \frac{1.25g}{69.72g/mole}=0.0179moles$

Moles of O = $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{0.43g}{16g/mole}=0.027moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Ga = $\frac{0.0179}{0.0179}=1$

For O = $\frac{0.027}{0.0179}=1.5$

The ratio of Ga : O = 1 : 1.5

To make in whole number we multiple ratio by 2, we get:

The ratio of Ga : O = 2 : 3

The mole ratio of the element is represented by subscripts in empirical formula.

The Empirical formula = $Ga_2O_3$

The empirical formula weight = 2(69.72) + 3(16) = 187.44 gram/eq

Now we have to calculate the molecular formula of the compound.

Formula used :

$n=\frac{\text{Molecular formula}}{\text{Empirical formula weight}}$

$n=\frac{187.44}{187.44}=1$

Molecular formula = $(Ga_2O_3)_n=(Ga_2O_3)_1=Ga_2O_3$

Therefore, the chemical of the compound is, $Ga_2O_3$

5 0

3 years ago

Which of the following combination of elements would result in covalent compound? * W X Y Z Vand X Wand Z Y and Z Wand y

TEA [102]

Answer:

C. Y & Z

Explanation:

V, W are imaginary metals here because their valence electrons are typically less than 4. X, Y, Z are non-metals and have higher valence electrons. Here, if V or W bind with X, Y, or Z we make ionic bond (because metal + non metal = ionic). But, if X binds with Y or Z or any combinations of any two of the three non-metals results in covalent bond (non metal + non metal = covalent).

Thus, Y and Z make covalent.

4 0

2 years ago

Please help a s a p!

ValentinkaMS [17]

Predator 1: wolves
Predator 2: foxes
Prey 1: bison
Prey 2: prairie dogs

3 0

3 years ago

The table shows the students data from an investigation about a plant growth and five plants of the same type what is the best w

NARA [144]

Answer:

This question is incomplete

Explanation:

The question is incomplete because of the absence of the table but since the question says there are data from an investigation about a plant growth and five other plants (making six) of the same type, the best way to display this type of data for analyst is to use the grouped bar chart. <u>The grouped bar chart will display the data obtained (from an investigation on plant growth) from different students on each of the six plants (of the the same type)</u>.

Colours are usually used to identify the bars (of a group) or could be used to separate the group from other groups but in this case, colours are better used to identify the bars of a group.

8 0

3 years ago

If I have 12 protons, how many neutrons and electrons would I need to make a stable atom?

lesantik [10]

Answer:

im pretty sure you need 15 in all but dont get mad it thats wrong, so you would i think need 3 neutrons

Explanation:

3 0

3 years ago