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3 years ago

These four ELEMENTS were found in early earth and they make up all living things.

Chemistry

2 answers:

Bogdan [553]3 years ago

7 0

Its is A. true ($:!:!:!:!::!/!!2!2$2$2$:$!:!.!.!.!.!:!!..!!:!:!:!:!:!:!!:!:!:!:!)))

VladimirAG [237]3 years ago

6 0

Answer: True

Air is a mixture of many things; it's not just Oxygen, but Hydrogen, Carbon, and Nitrogen as well are made up of air. Fun fact: Nitrogen is actually more abundant in air

You might be interested in

If two atoms have the same atomic numbers but different mass numbers, then they can be considered atoms of the same element.

castortr0y [4]

Same elements can have different nuclei. So, true.

7 0

3 years ago

Read 2 more answers

How many moles of mercury, Hg, are there in 1.30 x 10^7 atoms of murcury? PLEASE HELP, IT'S URGENT! Thank you! (:

vodka [1.7K]

1 mole Hg ---------------- 6.02x10²³ atoms
?? ------------------------- 1.30 x10⁷ atoms

1.30x10⁷ x 1 / 6.02x10²³ =

= 1.30x10⁷ / 6.02x10²³ => 2.159x10⁻¹⁷ moles

hope this helps!

7 0

3 years ago

You can practice converting between the mass of a solution and mass of solute when the mass percent concentration of a solution

LUCKY_DIMON [66]

<u>Answer:</u> The mass of solution having 768 mg of KCN is 426.66 grams.

<u>Explanation:</u>

We are given:

0.180 mass % of KCN solution.

0.180 %(m/m) KCN solution means that 0.180 grams of KCN is present in 100 gram of solution.

To calculate the mass of solution having 768 mg of KCN or 0.786 g of KCN (Conversion factor: 1 g = 1000 mg)

Using unitary method:

If 0.180 grams of KCN is present in 100 g of solution.

So, 0.768 grams of KCN will be present in = $\frac{100g}{0.180g}\times 0.768=426.66g$ of solution.

Hence, the mass of solution having 768 mg of KCN is 426.66 grams.

8 0

3 years ago

1. Una onda tiene una longitud de onda de 2 metros y una frecuencia de 1.5 Hz. ¿Cuál es su velocidad?

IrinaVladis [17]

Answer:

3 m/s

Explanation:

▲

usando la fórmula velocidad = frecuencia multiplicada por la longitud de onda.

v = (1.5)(2)

v= 3 m/s

6 0

3 years ago

An aqueous solution is listed as being 33.8% solute by mass with a density of 1.15 g/mL, the molar mass of the solute is 145.6 g

vodomira [7]

Answer:

A) 2.69 M

B) 0.059

Explanation:

A) We have:

33.8% solute by mass= 33.8 g solute/100 g solution

molarity = mol solute/ 1 L solution

molarity= $\frac{33.8 g solute}{100 g solution}$ x $\frac{1.15 g solution}{1 ml}$ x $\frac{1 mol solute}{145.6 g solute}$ x $\frac{1000 ml}{1 L}$

molarity= 2.69 mol solute/L solution = 2.69 M

B) We know that there are 33.8 g of solute in 100 g of solution.

As the total solution is compounded by solute+solvent (in this case, solvent is water), the mass of water is the difference between the mass of the total solution and the mass of solute:

mass of water= 100 g - 33.8 g = 66.2 g

Now, we calculate the number of mol of both solute and water:

mol solute= 33.8 g solute x $\frac{1 mol solute}{145.6 g}$ = 0.232 mol

mol H20= 66.2 g H₂O x $\frac{1 mol H2O}{18 g}$

Finally, the mol fraction of solute (Xsolute) is calculated as follows:

Xsolute= $\frac{mol solute}{total mol}= \frac{mol solute}{mol solute + mol H2O}=\frac{0.232 mol}{0.232 mol + 3.677 mol}$

Xsolute= 0.059

4 0

3 years ago