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2 years ago

An atom has a mass number of 9 and 5 neutrons. What is its atomic number? A 19 B. 14 O c.4 D. 11 SN

Chemistry

2 answers:

nika2105 [10]2 years ago

5 0

Answer:

$\boxed {\boxed {\sf C. \ 4}}$

Explanation:

First, define some important terms.

Mass number: the sum of the nucleons (protons and neutrons)
Atomic number: the number of protons

We know the mass number is 9. So, the sum of protons and neutrons is 9.

$mass \ number =9$

$protons + neutrons = 9$

We also know the atoms has 5 neutrons. Therefore, the rest must be protons.

$protons + 5 \ neutrons =9$

Subtract the 5 neutrons from the overall mass number of 9.

$protons = 9- 5 \ neutrons \\$

$protons=4$

There are 4 protons, so the atomic number is also 4. This atom is beryllium.

butalik [34]2 years ago

4 0

Answer:

C. 4

Explanation:

the mass is the number of neutrons and Protons. so if you have 5 neutrons that means the rest are Protons... and the number of Protons is the Atomic number meaning the Element number... Beryllium is the element :)

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2 years ago

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mafiozo [28]

Answer:

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Explanation:

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From the ideal gas law we assume that n = 1;

So;

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If we cross multiply;

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So;

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2 years ago

The reaction C 4 H 8 ( g ) ⟶ 2 C 2 H 4 ( g ) C4H8(g)⟶2C2H4(g) has an activation energy of 262 kJ / mol. 262 kJ/mol. At 600.0 K,

ludmilkaskok [199]

Answer: $4.3\times 10^{-13}s^{-1}$

Explanation:

According to the Arrhenius equation,

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or,

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where,

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R = gas constant = 8.314 J/mole.K

$T_1$ = initial temperature = $600.0K$

$T_2$ = final temperature = $775.0K$

Now put all the given values in this formula, we get

$\log (\frac{6.1\times 10^{-8}}{K_2})=\frac{262000}{2.303\times 8.314J/mole.K}[\frac{1}{600.0K}-\frac{1}{775.0K}]$

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Answer:

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Explanation:

<h2>Condensation is the change of water from its gaseous form (water vapor) into liquid water. Condensation generally occurs in the atmosphere when warm air rises, cools and looses its capacity to hold water vapor. As a result, excess water vapor condenses to form cloud droplets.</h2>

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An atom has a mass number of 9 and 5 neutrons. What is its atomic number? A 19 B. 14 O c.4 D. 11 SN​

An atom has a mass number of 9 and 5 neutrons. What is its atomic number? A 19 B. 14 O c.4 D. 11 SN