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3 years ago

What is the difference between mass number and atomic number

2 answers:

7 0

Mass number is the number of protons and neutrons in an atom.
Atomic mass is the average mass of all the isotopes of a certain type.

myrzilka [38]3 years ago

5 0

Atomic number is the number of protons that are inside that atom. This helps identify which element an atom is.

Atomic mass is the number of protons and neutrons inside an atom.

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Treatment of butanedioic (succinic) anhydride with ammonia at elevated temperature leads to a compound of molecular formula C4H5

artcher [175]

Answer:

The product is Methyl cyanoacetate

Explanation: see structure attached

5 0

3 years ago

Why Group 18 elements on the periodic table rarely form compounds

lawyer [7]

Most elements on group 18 are the Noble Gases. They already have a complete last level with 8 electrones. Actually they can form compounds but only on the lab and they will not even last half a second.

4 0

3 years ago

Is magnetism, reactivity, and fluorescence used to identify minerals

valkas [14]

Yes it is used , hope this helps

6 0

3 years ago

Identify the number of moles in 369 grams of calcium hydroxide. Use the periodic table and the polyatomic ion resource.

topjm [15]

Answer : The number of moles in 369 grams of calcium hydroxide is, 4.98 moles

Explanation : Given,

Mass of calcium hydroxide = 369 g

Molar mass of calcium hydroxide = 74.093 g/mole

Formula used :

$\text{Moles of calcium hydroxide}=\frac{\text{Mass of calcium hydroxide}}{\text{Molar mass of calcium hydroxide}}$

Now put all the given values in this formula, we get the moles of calcium hydroxide.

$\text{Moles of calcium hydroxide}=\frac{369g}{74.093g/mole}=4.98mole$

Therefore, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles

7 0

3 years ago

1. In general, the nucleus of a small atom is stable. Therefore, over very short distances, such as those in a small nucleus,

postnew [5]

<h3>1. Answer;</h3>

a. the strong nuclear force is much greater than the electric force.

<h3>Explanation;</h3>

For an atom to be stable it means it has enough amount of binding energy to hold its nucleus together permanently.
Therefore, an unstable atom lacks enough amount of binding energy to hold its nucleus permanently and thus undergoes decay to achieve stability. Unstable atoms are therefore referred to being radioactive.
Small atoms are stable; this is because they have equal number of protons and neutrons and thus the protons and neutrons fill up energy levels while maximizing the strong force binding the nucleus together.

<h3>9. Answer;</h3>

b. change into a different element altogether.

Uranium-238 undergoes alpha decay. Therefore, uranium-238 will change into a different element altogether.

<h3> Explanation;</h3>

Unstable atoms undergo radioactive decay in order to achieve stability of their nucleus.
Uranium-238 is an example of such atom, which may undergo decay to achieve stability.
Alpha decay is one of the types of decays, others being beta decay and gamma decay. In alpha decay the radioactive isotope undergoes decay such that its mass number is decreased by four and its atomic number is decreased by two.
Therefore, Uranium-238 undergoes alpha decay to form a different element whose mass number is 234 and atomic number is 90, known as thorium-234.

5 0

3 years ago

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