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4 years ago

Un-reactive elements include the last group of the periodic table.

1 answer:

4 0

True:

They are Nobel gassed! They are un-reactive because there outer shell (valence) is completely full. This means they do not want to lose or gain on electron so they do not react.

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Heliocentric and Geocentric

bulgar [2K]

Explanation:

heliocentric means having the sun in the middle/center in the solar system

geocentric means having the earth in the middle/center in the solar system

therefore your answers are:

the planets orbit the sun.

in 1543, Nicolaus Copernicus proposed the theory.

the evidence that led people to believe this was when Galileo observed that four moons orbited around Jupiter. in other words, heliocentric.

most of the stars are located in the milky way galaxy.

7 0

3 years ago

Describe how you could adjust the settings of the simulation to increase the number of red (H3O+) and blue (A-) particles in the

never [62]

Answer:

im so sorry i really need points

Explanation:

4 0

3 years ago

Read 2 more answers

Confused on what to do? Can someone explain this in a simple way?

aev [14]

Introduction of essay: talk about the three models used in science (mathematical, conceptual and physical), how do they help scientists understand complex ideas?, introduce the formula for density (as a mathematical model) and the particle model (as a conceptual model ... i think it is...) in science.

Body paragraph of essay: further discuss the properties of the models, link them to the examples (formula of density and the particle model) and compare and contrast (the strengths and weaknesses of each model) e.g. “Mathematical models help scientists to understand the underlying relationship between two concepts. Although a mathematical model is short and concise it is often hard to describe the model conceptually or physically and its therefore harder to get the full picture of how a scientific process works physically. A conceptual model is helpful for intuitive ideas in science like the particle model that would be harder to describe mathematically, due to how broad it is.” Etc etc.

Conclusion paragraph of the essay: “to conclude, models in science are important because they help us to understand difficult and intuitive ideas in a more clear and concise manner.” Etc etc.

Hope this helped - keep in mind that i don’t know the actual difference between conceptual and physical models so look through your books notes for more info for your essay.

6 0

3 years ago

Glucose, C6H12O6, is a good source of food energy. When it reacts with oxygen, carbon dioxide and water are formed. How many lit

Snezhnost [94]

Answer: The volume of carbon dioxide gas produced is 95.96 L

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of glucose = 126 g

Molar mass of glucose = 180.2 g/mol

Putting values in above equation, we get:

$\text{Moles of glucose}=\frac{126g}{180.2g/mol}=0.699mol$

The chemical equation for the combustion of glucose follows:

$C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O$

By Stoichiometry of the reaction:

1 mole of glucose reacts with 6 moles of carbon dioxide gas

So, 0.699 moles of glucose will produce = $\frac{6}{1}\times 0.699=4.194mol$ of carbon dioxide gas

At STP:

1 mole of a gas occupies 22.4 L of volume

So, 4.194 moles of carbon dioxide gas will occupy $\frac{22.4}{1}\times 4.194=95.96L$ of volume

Hence, the volume of carbon dioxide gas produced is 95.96 L

5 0

3 years ago

Heating a solution of alcohol and water, then collecting the alcohol vapors and condensing them into a liquid with higher alcoho

Sindrei [870]

Answer:

Distillation.

Explanation:

If we are heating a mixture of two miscible liquids and collecting the vapors it means we are separating the two mixtures from each other based on their boiling point differences.

This technique of separation of two liquids based on the difference in boiling point is known as Distillation.

Alcohol will evaporate easily as compared to water as water has stronger influence of hydrogen bond making the inter-molecular forces stronger.

4 0

4 years ago