3 years ago

An element has an atmomic number of 68. The number of protons and electron in a neutral atom of the element are?

Chemistry

1 answer:

Bess [88]3 years ago

8 0

Answer:

Explanation:

An element whose atomic number is 68 (number Z), has 68 electrons and 68 protons. According to the periodic table it corresponds to the element Erbium (Er), whose mass number (A) is 167. The number of neutrons is 167-68 = 99.

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Pure water at 25°C has a pH of<br> (1) 1 (2) 5 • (3) 7<br> (4) 14

Marysya12 [62]

Answer:

7. .........................

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2 years ago

H2S (g) + O2(g) -> SO2+ H2O, how many grams of O2 are needed to make 25.0 g of SO2 (Hint: balance the equation first)

vekshin1

Answer:

Hello

The answer is 18,7(b)

Explanation:we don't know the value of o² so at first we should put (x)instead of gr of o²and then write 1molO²/32grO²×2mol SO²/3mol O²×64gr SO²/1molSO²=25 gr SO².and then just find the value of (x).

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2 years ago

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Mariulka [41]

Answer:

0.9 moles of water

Explanation:

Use mole ratios:

5 : 6

divide by 5 on both sides

1 : 1.2

multiply by 0.75 on both sides

0.75 : 0.9

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(Please correct me if I'm wrong)

5 0

2 years ago

A gas at constant temperature has a pressure of 404.6 kPa with a volume of 12 ml. If the volume changes to 43ml, what is the new

blagie [28]

Answer:

The answer is

Explanation:

The new pressure can be found by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2$

Since we are finding the new pressure

$P_2 = \frac{P_1V_1}{V_2} \\$

404.6 kPa = 404600 Pa

From the question we have

$P_2 = \frac{404600 \times 12}{43} = \frac{4855200}{43} \\ = 112911.6279... \\ = 112912$

We have the final answer as

Hope this helps you

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Norma-Jean [14]

First one is reactants and then second one is products

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3 years ago