All categories

3 years ago

What elements in the building block for all other elements

1 answer:

6 0

Chlorine, oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, hydrogen, phosphorous and carbon make up over 99 percent of the earth's crust, atmosphere and oceans (by weight). These elements are truly "building blocks"—they combine with other elements to form our world.

Of the 92 natural elements, 25 are essential for life. There are six main elements that are the fundamental building blocks of life. They are, in order of least to most common: sulfur, phosphorous, oxygen, nitrogen, carbon, and hydrogen.

You might be interested in

If the molar absorptivity constant for the red dye solution is 5.56×104 M-1cm-1, calculate the molarity of the red dye solution

Shtirlitz [24]

Explanation:

a) Using Beer-Lambert's law :

Formula used :

$A=\epsilon \times c\times l$

where,

A = absorbance of solution = 0.945

c = concentration of solution = ?

l = length of the cell = 1.20 cm

$\epsilon$ = molar absorptivity of this solution = $5.56\times 10^4 M^{-1} cm^{-1}$

$0.945=5.56\times 10^4 M^{-1} cm^{-1}\times 1.20 \times c$

$c=1.4163\times 10^{-5} M=14.16 \mu M$

( $1\mu M=10^{-6} M$ )

14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.

b) $c=1.4163\times 10^{-5} mol/L$

1 L of solution contains $1.4163\times 10^{-5}$ moles of red dye.

Mass of $1.4163\times 10^{-5}$ moles of red dye:

$1.4163\times 10^{-5}\times 879.86g/mol=0.01246 g$

$(w/v)\%=\frac{\text{Mass of solute (g)}}{\text{Volume of solvent (mL)}}\times 100$

$red(w/v)\%=\frac{0.01246 g}{1000 mL}\times 100=0.001246\%$

c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.

Concentration of red dye solution = $c=1.4163\times 10^{-5} M$

Concentration of red solution after dilution = c'

$c=c'\times 5$

$1.4163\times 10^{-5} M=c'\times 5$

$c'=2.83\times 10^{-6} M$

The final concentration of the diluted solution is $2.83\times 10^{-6} M$

8 0

3 years ago

Why is acid added to water during eletrolysis

DedPeter [7]

Answer:

Pure water is a non conductor of electricity and dilute acids in their aqueous solutions form free ions, which conducts electricity. Thus when we need to electrolyse water, a dilute acid is added to increase its conductivity.

4 0

2 years ago

What determines the property of hardness in a mineral?

Rama09 [41]

Answer:

It's determined by the ability of one mineral to scratch another mineral.

5 0

2 years ago

It is required to prepare 1250 kg of a solution composed of 12 wt.% ethanol and 88 wt.% water. Two solutions are available, the

bekas [8.4K]

Answer:

437.5 kg of first solution and 812.5 kg of second solution should be mixed to get desired solution.

Explanation:

Let the mass of the first solution be x and second solution be y.

Amount solution required = 1250 kg

x + y = 1250 kg....[1]

Percentage of ethanol in required solution = 12% of 1250 kg

Percentage of ethanol in solution-1 = 5% of x

Percentage of ethanol in required solution = 25% of y

5% of x + 25% of y =12% of 1250 kg

$\frac{5}{100}\times x+\frac{25}{100}y=\frac{12}{100}\times 1250 kg$

x + 5y = 3000 kg...[2]

Solving [1] and [2] we :

x = 437.5 kg , y = 812.5 kg

437.5 kg of first solution and 812.5 kg of second solution should be mixed to get desired solution.

8 0

3 years ago

The elements chlorine and iodine have similar chemical properties because they _____. Group of answer choices have the same numb

worty [1.4K]

Answer:

Have the same number of electrons in their outer energy levels

Explanation:

Elements in the same group have similar chemical properties because they have the same number of valence electron(s) in their outermost shell.

Chlorine and Iodine have similar chemical properties because they have the same number of valence electron in their outermost shell. This can be seen from their electronic configuration as shown below:

Cl (17) => 1s² 2s²2p⁶ 3s²3p⁵

I (53) => [Kr] 4d¹⁰ 5s²5p⁵

From the above illustration:

Outer shell of Cl (3s²3p⁵) = 2 + 5 = 7 electrons

Outer shell of I (5s²5p⁵) = 2 + 5 = 7 electrons

Since they have the same number of valence electrons, therefore, they will have similar chemical properties.

7 0

3 years ago