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4 years ago

What does the arrangement of the periodic table help scientists see?

Chemistry

1 answer:

lina2011 [118]4 years ago

7 0

The relation between the elements electro negativity, atomic radius, and ionization energy levels.

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The switch is used to ___________ or __________ an electrical circuit. When the switch is on, the circuit is __________ , and wh

Pani-rosa [81]

Answer:

The switch is used to disconnect or connect an electrical circuit. When the switch is on, the circuit is complete, and when the switch is off, the circuit is open. Electrical current exists in the circuit when it is closed, but when it is open, there is no electrical current in the circuit. The switch determines whether the circuit is open and closed.

6 0

3 years ago

I need an example of a chemical change involving water.Pleaseeee.

slava [35]

Chemical change occur when two substances are combined and produces a new substance or decomposes into two or more substances which are entirely different from the original two substances.

There are three types of chemical changes. These are 1) Inorganic Changes, 2) Organic Changes, and 3) Biochemical Changes

Here are some examples of chemicsal changes.

If you combine Sodium and Water, chemical changes causes decomposition into Sodium Hydroxide and Hydrogen.

Sodium + Water ==> Sodium Hydroxide and Hydrogen

Na + H2O ====> NaOH and H

Another example of chemical change is:

Carbon Dioxide and Water will decompose into Sugar and Oxygen

Carbon Dioxide + Water ==> Sugar and Oxygen

CO2 + H2O ==> CnH2nOn (where n is between 3 and 7) and O

7 0

3 years ago

Calculate the standard enthalpy change for the reaction at 25 ∘ C. Standard enthalpy of formation values can be found in this li

meriva

Answer:

The standard enthalpy change for the reaction at $25^{0}\textrm{C}$ is -2043.999kJ

Explanation:

Standard enthalpy change ( $\Delta H_{rxn}^{0}$ ) for the given reaction is expressed as:

$\Delta H_{rxn}^{0}=[3mol\times \Delta H_{f}^{0}(CO_{2})_{g}]+[4mol\times \Delta H_{f}^{0}(H_{2}O)_{g}]-[1mol\times \Delta H_{f}^{0}(C_{3}H_{8})_{g}]-[5mol\times \Delta H_{f}^{0}(O_{2})_{g}]$

Where $\Delta H_{f}^{0}$ refers standard enthalpy of formation

Plug in all the given values from literature in the above equation:

$\Delta H_{rxn}^{0}=[3mol\times (-393.509kJ/mol)]+[4mol\times (-241.818kJ/mol)]-[1mol\times (-103.8kJ/mol)]-[5mol\times (0kJ/mol)]=-2043.999kJ$

4 0

3 years ago

What is the molecular formula of the structure below?

taurus [48]

Answer:

C₆H₆

Explanation:

Each border of the figure represents 1 atom of carbon. We have 6 borders = 6 atoms of carbon.

Each atom of carbon form 4 bonds. All the carbons are doing a double bond and a single bond with other carbons. That means are bonded 3 times. The other bond (That is not represented in the figure. See the image) comes from hydrogens. As we have 6 carbons that are bonded each 1 with one hydrogen. There are six hydrogens and the molecular formula is:

This structure is: Benzene

8 0

3 years ago

On what two days would the UK, Chile, South Africa, and Japan have an equal amount of day and night? O Winter Solstice and Summe

mario62 [17]

I say both equinox because winter solstice has the least amount of sunlight and the summer solstice has the most ampunt of daylight so i said both equinox

4 0

3 years ago