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2 years ago

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Element X forms an oxide with chemical formula X20. Experimental tests show that X20 contains 25.8 % oxygen, and x contains 74.2

% by mass.
(b) Use this information to identify element X.

1 answer:

lawyer [7]2 years ago

6 0

Hdhdhdh hdhdhdh hdhdhdh

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Please help!!! DUE IN 10 minutes

NARA [144]

Answer:

90

Th

232.04

Explanation:

90 - atomic number

Th - element symbol

232.04 - atomic mass

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2 years ago

Where in a data table should units of measurement be shown?

Vikentia [17]

The unites of measurement in a data table should be shown in the headings of some columns.

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3 years ago

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I need an answer now please asap and you will me marked brainiest please it's missing I need it now.

BaLLatris [955]

I really hope this helps I’ve been there too and I’m just doing this so I get the 20 words and I have the picture

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2 years ago

The Earth's moon is unusually large. Two popular theories of the moon's origin include the "sister world" hypothesis, which stat

Verizon [17]

Answer: D. They show that neither theory is complete and entirely correct.

Explanation:

Theory is the set of rules and principles that describe and explain a particular phenomenon (the existence of the moon in this case) and is subject to changes as new evidence emerges that gives meaning to it.

In this sense, there are many theories about the Earth's moon formation and two of the "accepted" theories are described before the question. In addition, both theories explain in a certain way the reason why the Moon is predominantly composed of elements similar to those found on Earth.

However, both theories seem to be incomplete when trying to explain our Moon's origin.

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3 years ago

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A solution was made by dissolving 5.10 mg of hemoglobin in water to give a final volume of 1.00 ml. the osmotic pressure of this

Assoli18 [71]

The molecular weight of hemoglobin can be calculated using osmotic pressure

Osmotic pressure is a colligative property and it depends on molarity as

πV = nRT

where

π = osmotic pressure

V = volume = 1mL = 0.001 L

n = moles

R = gas constant = 0.0821 L atm / mol K

T = temperature = 25°C = 25 + 273 K = 298 K

Putting values we will get value of moles

$moles=\frac{\pi V}{RT}=\frac{0.00195X0.001}{0.0821X298}mol$

we know that

$moles=\frac{mass}{molarmass}$

Therefore

$molarmass=\frac{mass}{moles}=\frac{5.10X10^{-3}g}{7.97X10^{-8}}=6.399X10^{4}g$

5 0

2 years ago