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3 years ago

How many neutrons does element X have if its atomic number is 30 and its mass number is 70?

1 answer:

3 0

The answer is 40.

We can solve this by finding out the number of protons, and neutrons. Atomic number of an element means the number of protons in that element. So, the atom has 30 protons if the atomic number is 30.

On the other hand, mass number is the total number of protons and neutrons, but not electrons, because they're too light comparing to the other 2. Therefore, we can simply solve the number of neutrons in the atom by subtracting the number of protons from the mass number. 70 - 30 = 40.

Therfore, the number of neutrons is 40.

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If an object what is 30 kg of mass is moving at 10 m/s to the right how much kinetic energy does it have

ki77a [65]

Explanation:

m=30

v=10

K.E=1/2mv^2

=1/2×30×10^2

=1/2×30×100

=1500 joule

6 0

2 years ago

Consider the following reaction: CO(g)+2H2(g)⇌CH3OH(g) Kp=2.26×104 at 25 ∘C. Calculate ΔGrxn for the reaction at 25 ∘C under eac

valentinak56 [21]

Answer : The value of $\Delta G_{rxn}$ is, $8.867kJ/mole$

Explanation :

The formula used for $\Delta G_{rxn}$ is:

$\Delta G_{rxn}=\Delta G^o+RT\ln Q$ ............(1)

where,

$\Delta G_{rxn}$ = Gibbs free energy for the reaction

$\Delta G_^o$ = standard Gibbs free energy

R = gas constant = 8.314 J/mole.K

T = temperature = $25^oC=273+25=298K$

Q = reaction quotient

First we have to calculate the $\Delta G_^o$ .

Formula used :

$\Delta G^o=-RT\times \ln K_p$

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

$\Delta G^o=-(8.314J/mole.K)\times (298K)\times \ln (2.26\times 10^{4})$

$\Delta G^o=-24839.406J/mole=-24.83\times 10^3J/mole=-24.83kJ/mole$

Now we have to calculate the value of 'Q'.

The given balanced chemical reaction is,

$CO(g)+2H_2(g)\rightarrow CH_3OH(g)$

The expression for reaction quotient will be :

$Q=\frac{(p_{CH_3OH})}{(p_{CO})\times (p_{H_2})^2}$

In this expression, only gaseous or aqueous states are includes and pure liquid or solid states are omitted.

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

$Q=\frac{(1.4)}{(1.2\times 10^{-2})\times (1.2\times 10^{-2})^2}$

$Q=8.1\times 10^{5}$

Now we have to calculate the value of $\Delta G_{rxn}$ by using relation (1).

$\Delta G_{rxn}=\Delta G^o+RT\ln Q$

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

$\Delta G_{rxn}=-24.83kJ/mole+(8.314\times 10^{-3}kJ/mole.K)\times (298K)\ln (8.1\times 10^{5})$

$\Delta G_{rxn}=8.867\times 10^3J/mole=8.867kJ/mole$

Therefore, the value of $\Delta G_{rxn}$ is, $8.867kJ/mole$

3 0

3 years ago

Low tide____.

Fantom [35]

Answer:

i think the answer is A

Explanation:

because in some areas, a regular pattern occurs of one high tide and one low tide each day,

8 0

3 years ago

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sashaice [31]

I think it's DNA forms a double helix and RNA consists a single strand.
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3 0

2 years ago

Read 2 more answers

Write the name and molecular formula of an organic compounds having its name suffixed with -ol and having 2 carbon atoms in the

777dan777 [17]

Ethanol C₂H₆O

Explanation:

When ethanol (CH₃-CH₂-OH) is heated in the presence of the sulphuric acid (H₂SO₄) it will produce ethylene (CH₂=CH₂ ) and water (H₂O).

CH₃-CH₂-OH → CH₂=CH₂ + H₂O

Learn more about:

sulphuric acid

brainly.com/question/867125

#learnwithBrainly

4 0

3 years ago