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Elis [28]
3 years ago
11

I NEED HELP RIGHT NOW

Chemistry
1 answer:
PolarNik [594]3 years ago
7 0
There are a total of 4 elements
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There are two naturally occurring isotopes of copper. 63cu has a mass of 62.9296 amu. 65cu has a mass of 64.9278 amu. determine
SSSSS [86.1K]
1) You need to use the atomic mass of copper.


You can find it in a periodic table. It is 63.546 amu.


2) The atomic mass is the weigthed mass of the different isotopes.


This is, the atomic mass of one element is the atomic mass of each isotope times its corresponding abundance:


=> atomic mass of the element = abundance isotope 1 * atomic mass isotope 1 + abundance isotope 2 *  atomic mass isotope 2 + ....+abundance isotope n * atomic mass isotope n.


3) The statement tells there are two isotopes so the abundance of one is x and the abundance of the other is 1 - x


=> 63.546 amu = x * 62.9296 amu + (1-x)*64.9278


=> 63.546 = 62.9296x + 64.9278 - 64.9278x


=> 64.9278x - 62.9296 = 64.9278 - 63.546


=> 1.9982x = 1.3818


=> x = 1.3818 / 1.9982 = 0.6915 = 69.15%


=> 1 - x = 1 - 0.6915 = 0.3085 = 30.85%


Answer:


Cu-63 69.15%;


Cu-65 : 30.85%
3 0
3 years ago
The product of alpha decay of the Nobelium isotope 259No is
Svet_ta [14]

Answer:

Nobelium is made by the bombardment of curium (Cm) with carbon nuclei. Its most stable isotope, 259No, has a half-life of 58 minutes and decays to Fermium (255Fm) through alpha decay or to Mendelevium (259Md) through electron capture.

Explanation:

7 0
3 years ago
Pharmacy technician measures the mass of a pill. The mass of one pill is
Galina-37 [17]
The mass of 100 pills would be 78000 mg and 0.078 kilograms.

Hope this helps you :)
8 0
3 years ago
Read 2 more answers
A mixture of propane and butane is fed into a furnace where it is mixed with air. the furnace exhaust leaves the furnace at 305°
IgorLugansk [536]
In this item, I supposed, that we are determine the molar fraction of oxygen and carbon dioxide in the sample. This can be done by dividing their respective partial pressures by the total pressure of the sample.

   O2 : mole fraction = (100.7 mmHg) / (763.00 mmHg)  = 0.13

   CO2 : mole fraction = (33.57 mmHg) / (763.00 mmHg) = 0.044

Answers: O2 = 0.13
               CO2 = 0.044
3 0
3 years ago
The graph shows the volume of a gaseous product formed during two trials of a reaction. A different concentration of reactant wa
solniwko [45]

A: Trial 1, because the average rate of the reaction is lower.

The rate of reaction is the speed with which reactants are converted into products. It is also the rate at which reactants disappear and products appear.  The higher the rate of reaction, the greater the amount of product formed in a reaction.

If we look at the graph, we will realize that trial 1 produces a lesser amount of product than trial 2. This implies that the  average rate of the reaction in trial 1 is lower than in trial 2.

Lower average rate of reaction implies lower concentration of the reactants since the rate of reaction depends on the concentration of reactants.

Hence trial 1 has a lower concentration of reactants because the average rate of the reaction is lower.

8 0
3 years ago
Read 2 more answers
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