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statuscvo [17]
3 years ago
5

A mystery element has 18 protons. Which one of the following statements is true about the element?

Chemistry
1 answer:
Anastasy [175]3 years ago
4 0

Answer:

B

Explanation:

Elements in a group are determined by the number of valence electrons

Elements in a period are determined by the number of electrons shell

The electronic configuration of the element is

2,8,8

the number of valence electron is 8 that means it is in Group 8/O

the number of electron shell is 3 that means it is in period (row) 3

Group 8/O elements are called Noble gases

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Convert the following into balanced equations:
sesenic [268]

Gallium metal is heated in oxygen gas, it melts and forms solid gallium(III) oxide.

             Ga + O₂⇒   Ga O₂

Balance the atoms with simple - whole coefficients.

4 Ga + 3 O₂   2 Ga₂O₃.

Specify the states of matter.

4 Ga(s)  + 3 O₂ (g) ⇒   2 Ga₂O₃.(s)

Therefore, balanced equation is----- 4 Ga(s)  + 3 O₂ (g)  ⇒ 2 Ga₂O₃.(s)

What is the balanced formula equation?

A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction.

Why are equations balanced?

A balanced equation obeys the Law of Conservation of Mass. This is an important guiding principal in science. Finally, a balanced equation lets up predict the amount of reactants needed and the amount of products formed.

Learn more about balanced equation:

brainly.com/question/11904811

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4 0
2 years ago
A student conducting the iodine clock experiment accidentally makes an s2o32- stock solution that is too concentrated. how will
cupoosta [38]
Adding (S2O3)2- would affect the reaction mechanism that involves this ion. From the reaction mechanism given above, the equilibrium of step 2 would be affected. Adding the stock solution of (S2O3)2- would shift the equilibrium to the right thus making more products of the said mechanism. Also, the reaction rate of this step would occur faster than the original rate. This is based on Le Chatelier's Prinicple which states that a corresponding change would happen to the equilibrium of a reaction when pressure, concentration of the substances or temperature is changed. So, that after the addition, a color change would appear immediately because I3- would be removed slowly from solution, and would therefore be able to react with starch. 

8 0
3 years ago
How does black and coloured objects absorb light and convert it into heat?
Nezavi [6.7K]

Answer:

Light energy can be converted into heat energy. A black object absorbs all wavelengths of light and converts them into heat, so the object gets warm. A white object reflects all wavelengths of light, so the light is not converted into heat and the temperature of the object does not increase noticeably.

5 0
3 years ago
Explain in terns of atomic structure why barium has a lower first ionization energy than magnesium.
Sonja [21]

Answer:

Barium has a greater radius than magnesium

Explanation:

Barium and magnesium are two elements which belong to the same group, group 2A. This means that the two elements have two valence electrons in their outer shell.

The difference is, however, since barium is lower in group than magnesium, it has more electron shells than magnesium and, therefore, its radius is greater. The attraction force between the nucleus and the valence electrons in barium is lower as a result, as force is inversely proportional to distance. Hence, a lower amount of energy is required to remove the valence electrons from barium.

3 0
3 years ago
Evaluate the exponential expression (−2)6.
Olegator [25]

A general exponential expression is something like:

A^n

This means that we need to multiply the number A by itself n times.

Using that we will get (-2)^6 = 64

With that definition, we can rewrite:

(-2)^6 = (-2)*(-2)*(-2)*(-2)*(-2)*(-2)

So we just need to solve the above expression.

Also, remember the rule of signs:

(-)*(-) = (+)

We will get:

(-2)*(-2)*(-2)*(-2)*(-2)*(-2) =  [(-2)*(-2)]*[(-2)*(-2)]*[(-2)*(-2)]

                                        =  4*4*4 = 16*4 = 64

Then we got:

(-2)^6 = 64

If you want to learn more, you can read:

brainly.com/question/17172630

6 0
3 years ago
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