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2 years ago

11

Please help me !!!!

1 answer:

just olya [345]2 years ago

3 0

Answer:

12, 28, 16

Explanation:

If we are trying to find mass, neutrons are our guy. 28 "mass points" means 28 neutrons. Each neutron is one point

We know there are 12 protons and electrons if we look at a table of elements, the number in the top-left is always the number of protons and we can subtract mass from the protons to get our electrons

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True or false? an element consists of only single atoms of that element. <br> a. True <br> b. False

larisa [96]

From what i read, the answer should be b--false

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3 years ago

BartSMP [9]

Answer:

0.131 mol

Explanation:

To convert grams to moles, you need to use the molar mass. The molar mass is the mass number. You can find this on the periodic table. The molar mass of sodium is 22.990 g/mol.

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2 years ago

The reaction C4H8(g)⟶2C2H4(g) C4H8(g)⟶2C2H4(g) has an activation energy of 262 kJ/mol.262 kJ/mol. At 600.0 K,600.0 K, the rate c

crimeas [40]

Answer : The rate constant at 785.0 K is, $1.45\times 10^{-2}s^{-1}$

Explanation :

According to the Arrhenius equation,

$K=A\times e^{\frac{-Ea}{RT}}$

or,

$\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]$

where,

$K_1$ = rate constant at $600.0K$ = $6.1\times 10^{-8}s^{-1}$

$K_2$ = rate constant at $785.0K$ = ?

$Ea$ = activation energy for the reaction = 262 kJ/mole = 262000 J/mole

R = gas constant = 8.314 J/mole.K

$T_1$ = initial temperature = $600.0K$

$T_2$ = final temperature = $785.0K$

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

$\log (\frac{K_2}{6.1\times 10^{-8}s^{-1}})=\frac{262000J/mole}{2.303\times 8.314J/mole.K}[\frac{1}{600.0K}-\frac{1}{785.0K}]$

$K_2=1.45\times 10^{-2}s^{-1}$

Therefore, the rate constant at 785.0 K is, $1.45\times 10^{-2}s^{-1}$

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Answer:

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2 years ago

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inn [45]

It allows to test a inference, and analyze data to determine if the inference of the observation was correct.

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