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Alex_Xolod [135]
3 years ago
11

A radioactive sample has a half-life of 5 hours. What fraction of the sample will be left after 15 hours?​

Chemistry
1 answer:
DedPeter [7]3 years ago
6 0

Explanation:

hiiiii beautiful.........

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If 15 grams of Carbon dioxide is produced in a chemical reaction, how many grams of Carbon must be consumed in the reaction if w
guajiro [1.7K]

Answer:

Quantity of Carbon is 4.09 gm

Explanation:

Equation of carbon reacting with oxygen to give carbon dioxide is given by

C + O_{2} ⇒ CO_{2}

One mole of carbon reacts with one mole of Oxygen in this reaction to give One mole of Carbon dioxide.

So, 12 gm of carbon reacts with 32 gm of Oxygen in this reaction to give 44 gm of carbon dioxide.

15 gm of CO_{2} was formed in this reaction

Oxygen used in this reaction = \frac{15}{44}×32 = 10.91 gm ,

Thus Oxygen is in sufficient quantity in the reaction.

Now,

Carbon that must be used = \frac{15}{44}×12  = 4.09 gm.

5 0
3 years ago
What is true of all atoms?
Klio2033 [76]

Answer:

Atoms are the building blocks of matter. They are the smallest particles of an element that still have the element's properties. All atoms are very small, but atoms of different elements vary in size. Three main types of particles that make up all atoms are protons, neutrons, and electrons.

Explanation:

7 0
3 years ago
Read 2 more answers
Read the chemical equation.
Sladkaya [172]

Answer:- D. 1.8 moles of Fe and 2.7molCO_2 .

Solution:- The balanced equation is:

Fe_2O_3+3CO\rightarrow 2Fe+3CO_2

let's first figure out the limiting reactant using the given moles and mol ratio:

1.8molFe_2O_3(\frac{3molCO}{1molFe_2O_3})

= 5.4 mol CO

From calculations, 5.4 moles of CO are required to react completely with 1.8 moles of Iron(III)oxide but only 2.7 moles of CO are available. It means CO is limiting reactant.

Products moles depends on limiting reactant. Let's calculate the moles of each reactant formed for given 2.7 moles of CO.

2.7molCO(\frac{2molFe}{3molCO})

= 1.8 mol Fe

2.7molCO(\frac{3molCO_2}{3molCO})

= 2.7molCO_2

So, the correct choice is D.  1.8 moles of Fe and 2.7molCO_2 are formed.

6 0
3 years ago
Match the statements with the atmospheric layer they describe.
vekshin1

The correct matches are:

1. Exosphere - Temperatures reach as high as 2000 C yet it feels very cold

This is the top layer of the atmosphere. The atoms are so dispersed that despite it having very high temperature it doesn't feel like it at all.

2. Thermosphere - Particles that have enough energy can escape into space

The thermosphere is the fourth highest layer of the atmosphere. The atoms in this layer are relatively distant from one another, so the particles that have enough energy manage to escape easily into the exosphere and then the space.

3. Mesosphere - It is the coldest region of the atmosphere

The mesosphere is the third highest layer. In this layer the temperatures constantly drop, and they go down to -85 degrees, making it the coldest layer by far.

4. Stratosphere - Ninety percent ozone is in this layer

The startosphere has a separte zone in it which is dominated by only one gas, the ozone. It is called the ozone layer, the one that protects the Earth from too intense UV radiation, and in fact over 90% of this gas is locate here.

5. Troposphere - It is warm due to the heat from Earth's surface

The troposphere is the densest and lowest of the layers. It is the one that also has Greenhouse gases which manage to trap the heat that is radiated from the surface of the Earth, thus keeping this layer relatively warm.

6 0
4 years ago
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Ribosomes are cell structures that make
Vitek1552 [10]

Answer:

Ribosomes preform biological synthesis. (mRNA Translation). They also link amino acids together to form polypeptide chain.

8 0
3 years ago
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