What did the experiments of scientists after John Dalton reveal about his

Write the nuclear equation for the beta decay of Aluminum-25.

Brums [2.3K]

We want to write the nuclear equation for the beta decay of Aluminium-25.

The equation is:

$^{25}_{13}Al \implies ^{25}_{14}Si + ^{0}_{-1}e$

First, as you may know, in a beta decay the number of protons is increased by one. Aluminium has 13 of them, so after the decay, we will have 14 protons.

This means that the aluminium will transform into silicon, then the nuclear equation is just:

$^{25}_{13}Al \implies ^{25}_{14}Si + ^{0}_{-1}e$

Where the:

$^{0}_{-1}e$

Is an electron, which is the emitted particle in the beta decay.

If you want to learn more, you can read:

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3 0

3 years ago

1. Sodium and water react according to the following equation. If 31.5g of sodium are added to excess water, how many liters of

Vika [28.1K]

<h3> Question 1</h3>

The number of liter of hydrogen gas that are formed at STP is

15.344 L

<u><em> calculation</em></u>

calculate the moles of Na

moles =mass/molar mass

from periodic table the molar mass of Na = 23 g/mol

moles = 31.5 g /23 g /mol = 1.37 moles

From equation above the mole ratio of Na: H2 is 2:1

therefore the moles of H2 =1.37 x1/2 =0.685 moles

At STP 1 moles of a gas = 22.4 L

0.685 moles = ? L

by cross multiplication

=[ (0.685 moles x 22.4 L) / 1 mole =15.344 L

<h3> Question 2</h3>

The percent yield = 84.77%

<u><em>calculation</em></u>

4 Na + O₂ → 2 Na₂O

%yield =actual yield / theoretical yield x 100

Actual yield= 61.8 g

<em>The theoretical yield is calculated as below</em>

Step 1: find the moles of Na

moles = mass /molar mass

from periodic table the molar mass of Na = 23 g/mol

moles = 54.1 g /23 g/mol =2.352 moles

Step 2: use the mole ratio to determine the moles of Na₂O

Na:Na₂O is 4: 2 therefore the moles of Na₂O = 2.352 x 2/4 =1.176 moles

Step 3: find the theoretical mass of Na₂O

mass = moles x molar mass

The molar mass of Na₂O = [(23 x 2 ) + 16] =62 g/mol

mass = 1.176 moles x 62 g/mol = 72.9 g

% yield is therefore = 61.8 g /72.9 x 100 = 84.77%

8 0

3 years ago

2. You water three sunflower plants with salt water. Each plant receives a different

wlad13 [49]

Answer:

Independent variable, is the amount of salt water received by each plant

Dependent variable, is the height of each plant

Control group, is the fourth plant that received pure water.

Note: The question is incomplete. The complete question is as follows: For the following experiments, define the independent variable (IV), dependent variable (DV) and control group (CG).

2. You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured.

Explanation:

Independent variable: An independent variable is a variable that an experimenter changes or controls and which has a direct effect on the dependent variable.

In the experiment above, the independent variable is the amount of salt water received by each plant because it is under the control of the experimenter and also is thought to have a direct effect on the height of plants.

Dependent variable: A dependent variable is a variable that is being measured or studied in an experiment, and it depends on the independent variable for its results.

The height of the plants is the dependent variable as it depends on the amount of salt water the plant receives.

Control group: The control group is the group in an experiment or study that does not receive the treatment as the other groups being studied and as such, is not influenced by the independent variable. Therefore, it is used as a standard for the other groups under study.

In this experiment, the control group is the fourth plant that received pure water.

3 0

3 years ago

If 6.49 mol of ethane (C2H6) undergo combustion according to the unbalanced equation

MArishka [77]

Answer:

22.715 moles of oxygen are used

Explanation:

Given data:

Number of moles of ethane = 6.49 mol

Number of moles of O₂ required = ?

Solution:

Chemical equation:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Now we will compare the moles of oxygen with ethane.

C₂H₆ : O₂

2 : 7

6.49 : 7/2×6.49 = 22.715 mol

Thus, 22.715 moles of oxygen are used.

3 0

3 years ago

3- Um tipo de nutriente complexo presente

umka21 [38]

Answer:

The human body when metabolizing meat, milk or eggs, being high in protein, manufactures uric acid as a metabolite, and releases more urea in the urine.

Uric acid generates an increased retention of liquid or water, that is why people who ingest excessively meat suffer from GOTA disease.

Gout disease is systemic and life-threatening puffiness.

Furthermore uric acid is an organic compound of carbon, nitrogen, oxygen and hydrogen. Its chemical formula is C5H4N4O3. It is found in urine in small amounts.

And urea is defined as a renal parameter from the quantitative point of view; It is a colorless, crystalline chemical compound of formula CO (NH2) 2. It is found abundantly in urine and faeces.

Explanation:

To have an accurate idea of the function of the kidneys, it is sufficient to carry out a simple blood test with determination of Urea and creatinine and an analysis of a urine sample in which the presence of cells (red blood cells and leukocytes) is assessed. and / or proteins (albumin). Today these 2 types of analysis are part of the routine of any analytical study.

4 0

3 years ago