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12345 [234]
3 years ago
11

¡¡¡PLEASE HELP!!! I'm stuck on a question..

Chemistry
1 answer:
Reptile [31]3 years ago
7 0

 The half  life  of uranium- 238  is

 4.46 x10^9  years


 Explanation

Half life  is the time  taken for  the  radioactivity  of   a isotope  to fall  to half  its  original  value.

The  original   mass  of uranium-238  is  4.0 mg

  Half  of original  mass of uranium  = 4.0  mg /2 = 2.0  mg

since  it  take 4.46  x 10^ 9 years  for  the sample   to half  the half life of uranium -238 = 4.46 x10^9 years

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Explain the relationship between the mole, particles, grams, and Liters.
Mamont248 [21]

Answer:A mole is an arbitrary number of molecules in a single unit - refer to avogadro's number. Essentially, 1 mole is 6.022x10^23 molecules for ALL molecules or atoms, however one must remember that not all atoms/molecules are the same size, this is where mass comes into play. When you measure out 2 grams of carbon powder, there will be a lot more molecules present than if you weighed out 2 grams of thorium powder; this is because carbon is much smaller - kind of like a car filled with clowns, one given car can hold a lot of small clowns but only a few big ones; so the same volume is occupied but the amount of substance (clowns) varies on their own size. The arbitrary mass (relative to the hydrogen atom) for a molecule is the sum of its atomic components' atomic masses; e. g. C2H6's will have 2x12.00 (carbon) + 6x1.01 (hydrogen) = ~30 grams / mole.

Explanation:

8 0
3 years ago
Which best describes how magnesium (Mg) and oxygen (O) bond?
Ksivusya [100]

Answer:

a

They form an ionic bond by exchanging two electrons.

Explanation:

Magnesium loses two electrons and oxygen gains these electrons so ionic bond is formed

8 0
3 years ago
In the periodic table, how are elements in the same group related to each other? A. They have the same atomic mass. B. They have
Irina-Kira [14]
Elements in the same group tend to have very similar properties (D). This is due to the number of valence electrons each group has.
3 0
3 years ago
Read 2 more answers
The molecular weight of NaCl is 58.44 grams/moles. How many grams of NaCl are found in a beaket with 100 ml of a 0.0050 M soluti
Viktor [21]

Answer:

The mass of NaCl is 0.029 grams

Explanation:

Step 1: Data given

Molecular weight of NaCl = 58.44 g/mol

Volume of solution = 100 mL = 0.100 L

Molarity = 0.0050 M

Step 2: Calculate moles NaCl

Moles NaCl = molarity * volume

Moles NaCl = 0.0050 M * 0.100 L

Moles NaCl = 0.00050 moles

Step 3: Calculate mass NaCl

Mass NaCl = moles NaCl * molar mass NaCl

Mass NaCl = 0.00050 moles * 58.44 g/mol

Mass NaCl = 0.029 grams

The mass of NaCl is 0.029 grams

4 0
3 years ago
How many liters of Cl2 gas will you have if you are using 63 g of Na?
ELEN [110]

Answer:

You will have 19.9L of Cl2

Explanation:

We can solve this question using:

PV = nRT; V = nRT/P

<em>Where V is the volume of the gas</em>

<em>n the moles of Cl2</em>

<em>R is gas constant = 0.082atmL/molK</em>

<em>T is 273.15K assuming STP conditions</em>

<em>P is 1atm at STP</em>

The moles of 63g of Cl2 gas are -molar mass: 70.906g/mol:

63g * (1mol / 70.906g) = 0.8885 moles

Replacing:

V = 0.8885mol*0.082atmL/molK*273.15K/1atm

V = You will have 19.9L of Cl2

6 0
3 years ago
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