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2 years ago

How can you use evidence to determine if a change is physical or chemical?

2 answers:

7 0

A physical change has Color, Shape, and anything that is physically changed. A chemical change is when you can’t really tell for example when a formation of new atoms. Even creating 1 or more new substances.

irakobra [83]2 years ago

4 0

Physical change is the color, shape stuff like that and chemical change is once it’s changed it can’t go back

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Near Cozumel, Mexico, a scuba diver goes down 60 ft to look at the sea creatures. As she descends, the air pressure increases. W

Rudik [331]

Answer: Boyle's Law

Explanation:

Boyle's Law which is also called Mariotte's law was formulated by physicist Robert Boyle in 1662.

It posits that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature.

As the Scuba Diver went deeper, the volume of air dropped so the pressure increased.

Please do react or comment to the answer if you have any issues or if you feel like this helped you so we can help others as well. Thank you.

5 0

2 years ago

Jane is sliding down a slide. What kind of motion is she demonstrating?

svp [43]

It is translational motion. i know because i found it on this site. its verified too, have a nice day

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2 years ago

Read 2 more answers

the atomic mass of N is 14.01 g/mol and the atomic mass of H is 1.008 g/mol. what is the molecular mass of NH3

nikdorinn [45]

Molecular mass= (14.01∗1)+(1.008∗3)
14.01+3.024=17.03g/mol

7 0

2 years ago

Match the following items. Match the items in the left column to the items in the right column. 1. general or nonspecific observ

ivann1987 [24]

when column B is like the attached pic: (missing in your question)

so the matches will be like that:

1- Qualitative :

as Qualitative is a general or nonspecific observation, they also don't require

measurements and even can't be measured, that is because of the reality is

being approximated only. It describes qualities and uses opinion

2- Hypothesis :

as a hypothesis is an educated guess quantitative, and it is a prediction stated

in " If and then " form. a hypothesis to be valid need a research such as:

-Encyclopedia & state and local research facilities & scientific journals.

3- Direct relationship:

as a Direct relationship is when two variable change in the same direction,

and one remaining larger than the other by the same factory.

- this is a type of a relationship in which there is a change with one variable, and corresponding with the change in the other. and because this corresponding change with the other variable in the same direction so it refers to a positive relationship.

4- Quantitative:

as Quantitative is a measured observation, It's an information or data based

on quantities obtained. And using numbers, equipment and standard units.

5- Control :

as control is standard, reference data or experiment qualitatively. this is what

you compare your experimental results to. This is for comparing results, it

used as a standard for comparison and use baseline measurements to use in

the comparing.

6- Theory :

as Theory is a presently accepted explanation of how something happened.

Scientifically acceptable general principles to explain phenomena. It the

general or abstract principles of the science. for example the wave theory of

light.

7- Law :

as a law is a statement that explains what something does under the same

conditions. when we take about law in science, it is a general rule to explain

the observations in the form of a mathematical statement. Scientific law may

be stated in words or expressed as a mathematical equations.

8- Best fit curve:

as best fit curve is a curve drawn to average the data's deviations direct

relationship. It is a process of constructing a curve that has best fit to a

series of data points.

7 0

2 years ago

Under standard-state conditions, which of the following species is the best reducing agent? a. Ag+ b. Pb c. H2 d. Ag e. Mg2+

eimsori [14]

Answer: The correct answer is Option b.

Explanation:

Reducing agents are defined as the agents which help the other substance to get reduced and itself gets oxidized. They undergo oxidation reaction.

$X\rightarrow X^{n+}+ne^-$

For determination of reducing agents, we will look at the oxidation potentials of the substance. Oxidation potentials can be determined by reversing the standard reduction potentials.

For the given options:

Option a: $Ag^+$

This ion cannot be further oxidized because +1 is the most stable oxidation state of silver.

Option b: $Pb$

This metal can easily get oxidized to $Pb^{2+}$ ion and the standard oxidation potential for this is 0.13 V

$Pb\rightarrow Pb^{2+}+2e^-;E^o_{(Pb/Pb^{2+})}=+0.13V$

Option c: $H_2$

This metal can easily get oxidized to $H^{+}$ ion and the standard oxidation potential for this is 0.0 V

$H_2\rightarrow 2H^++2e^-;E^o_{(H_2/H^{+})}=0.0V$

Option d: $Ag$

This metal can easily get oxidized to $Ag^{+}$ ion and the standard oxidation potential for this is -0.80 V

$Ag\rightarrow Ag^{+}+e^-;E^o_{(Ag/Ag^{+})}=-0.80V$

Option e: $Mg^{2+}$

This ion cannot be further oxidized because +2 is the most stable oxidation state of magnesium.

By looking at the standard oxidation potential of the substances, the substance having highest positive $E^o$ potential will always get oxidized and will undergo oxidation reaction. Thus, considered as strong reducing agent.

From the above values, the correct answer is Option b.

8 0

2 years ago