2 years ago

How many element are there on the periodic table?

Chemistry

2 answers:

Marina CMI [18]2 years ago

7 0

Answer:

118 elements

Hope that helps

givi [52]2 years ago

5 0

Answer:118

Explanation: it’s right

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3 years ago

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What mass of water must be added to 5g of nacl to make 5% mass persentage of the solution?

Vitek1552 [10]

Answer:-

95 grams

Explanation:-

Let the mass of water to be added be M

So total mass = 5 + M

So 5% of this solution has 5g of NaCl by mass.

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M+5 = 5 x 100/5

M+5=100

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3 years ago

In Thomson’s model of the atom , what parts of the atom were in motion

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madreJ [45]

Answer:

$470\frac{KJ}{mol}$

Explanation:

The activation energy represents the energy barrier that reagents must pass to transform into products (or products to transform into reagents in a reverse reaction)

For any reaction, the change in enthalpy is related to the activation energy by the equation

$\Delta H =E_{a\ direct}-E_{a\ reverse}$

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What type of compound is calcium oxide

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A carbonate because the oxygen neutralizes the reactive coding of the calcium in its original form.

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