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2 years ago

An ion from a given element has 20 protons and 18 electrons.

Chemistry

1 answer:

Gre4nikov [31]2 years ago

3 0

Explanation:

charges is +2

elements is CALCIUM

Symbol is Ca++

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What happens to temperature and kinetic energy of particles during a change of state

Wittaler [7]

When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant

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3 years ago

Suzanne makes a tower out of six identical plastic box. Then she uses a pan balance to measure the mass of the tower. She finds

choli [55]

Take the 72 g and divid it by 6 which would equal 12 g each

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3 years ago

What is the halogen in period 5?? it has six letters

Misha Larkins [42]

Simple,

take a look at your periodic table, if you have it labeled look at the Halogen

Group, it includes: Flourine, Chlorine, Bromine, Iodine, and Astatine.

Now, a period on the periodic table is read from left to right, and goes

down the rows of the periodic table.

Go to Period 5, go all the way to the Halogens, what is there?

Iodine.

Thus, your answer.

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3 years ago

Determine ΔH for the reaction CaCO3 → CaO + CO2 given these data: 2 Ca + 2 C + 3 O2 → 2 CaCO3 ΔH = −2,414 kJ C + O2 → CO2 ΔH = −

kicyunya [14]

Answer:

The ΔH for the reaction is -456.5 KJ

Explanation:

Here we want to determine ΔH for the reaction;

Mathematically;

ΔH = ΔH(product) - ΔH(reactant)

In the case of the first reaction;

ΔH = ΔH(CaO) + ΔH(CO2) - ΔH(CaCO3) ...........................(*)

From the other reactions, we can get the respective ΔH for the individual molecule in the reaction

In second reaction;

Kindly note that for elements, molecule of gases, ΔH = 0

What this means is that throughout the solution;

ΔH(Ca) = 0 KJ

ΔH(O2) = 0 KJ

ΔH(C) = 0 KJ

Thus, in writing the equation for the subsequent chemical reactions, we shall need to write and equate the overall ΔH for the reaction to that of the product alone

So in the second reaction

ΔH = 2ΔH(CaCO3)

Thus;

-2414/2 = ΔH(CaCO3)

ΔH(CaCO3) = -1,207 KJ

Moving to the third reaction, we have;

ΔH = ΔH(CO2)

Hence ΔH(CO2) = -393.5 KJ

For the last reaction;

ΔH = ΔH(CaO)

Hence ΔH(CaO) = -1270 KJ

Going back to equation *

ΔH = ΔH(CaO) + ΔH(CO2) - ΔH(CaCO3)

Using the values of the ΔH of the respective molecules given above,

ΔH = -1270 + (-393.5) - (-1207)

ΔH = -456.5 KJ

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3 years ago

Oxidation no of carbon in C3H7OH

mestny [16]

Answer:

-2

Explanation:

7 x 1 - 2 x 1 + 1 x 1 + 3C = 0 (no charge)

6 + 3C = 0

C = -2

6 0

3 years ago