Silicon dioxide is the compound
I need helppp pleaseee
Answer:
9) 126.86 amu
10) 197.26 amu
11) 55.83531 amu
or 55.8 amu (to 3 s.f.)
13) 14.07 amu
Explanation:
Please see attached picture for full solution.
A scientist designed a foam container to help keep frozen foods from melting. Which best explains how the foam works? It removes thermal energy from the air inside the container. It removes thermal energy from the frozen foods inside the container. It reduces the amount of thermal energy that is transferred from inside to outside the container. It reduces the amount of thermal energy that is transferred from outside to inside the container.
Answer:
It reduces the amount of thermal energy that is transferred from outside to inside the container.
Explanation:
Remember that thermal energy = heat. Also foam cannot remove thermal energy, it is an insulator meaning it prevents the transfer of thermal energy.
First choice: Foam cannot just remove thermal energy
Second: Again foam does not remove energy
Third: This would mean the heat would continue to stay in the container, leading to the frozen foods melting
Fourth: Correct, it reduces the amount of outside heat from entering the container, thus preventing melting
The foam helps by preventing the transfer of thermal energy from outside to inside the container. Option D is correct.
What is Thermal energy?The energy in the molecules is due to temperature. Thermal energy transfers always from high temperature to low temperature until equilibrium.Here, the temperature of the frozen food is much lesser than the surrounding environment. The transfer of energy is from the environment to the food objects.Therefore, the foam helps by preventing the transfer of thermal energy from outside to inside the container.
Learn more about Thermal energy:
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A block of pine wood has a mass of 120 g and a volume of 300 cm3. What is the density of wood? (Show your work)
Answer:
The answer is
0.4 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} [/tex]
From the question
mass of wood = 120 g
volume = 300 cm³
So the density of the wood is
[tex]density = \frac{120}{300} \\ = \frac{12}{30} = \frac{2}{5} [/tex]
We have the final answer as
0.4 g/cm³Hope this helps you
PLEASE HELP!! 50 POINTS!!! WILL MARK BRAINLEST!!!!
Think of a chemical reaction that you've seen in your daily life. Write a 3-5 sentence paragraph, explaining what it is and how you know it was a chemical reaction.
Answer:
Baking soda mixed with Vinegar
Explanation:
This is a chemical reaction that I have seen in my daily life. Vinegar is acidic while baking soda is a base. The 2 mix together to form carbonic acid and sodium acetate from sodium and bicarbonate ions.
It occurred to me not too long ago that I have multiple chemical reactions happen every day when I eat. The chemicals in my saliva break down the food I am eating. The pH in saliva is higher, so it breaks down the carbohydrates in the food I'm eating preparing it to go into my stomach and digest. There are also many reactions that must occur during digestion, such as the stomach acid breaking down the food further.
Why is ammonification an important process?
A) Bacteria converts ammonia into nitrites and nitrates that plants can use.
B) Fungi convert nitrogen in dead plants into ammonium, which converts proteins into ammonia.
C) Nitrogen is converted into a useable form through lightning fixation.
D) Plant enzymes reduce nitrogen compounds into amino acids.
(yes i’m aware this is biology and not chem)
Answer: B) Fungi convert nitrogen in dead plants into ammonium, which converts proteins into ammonia.
Helen recorded the following data about the half-life of a radioisotope. Radioactive Decay of Radioisotope A Grams of Radioactive Material Remaining Time (in billions of years) 200 0 100 1 50 2 25 3 12.5 4 6.25 5 Which of the following types of graphs could Helen use to best organize her data? A. bar graph B. line graph C. histogram D. circle graph
Answer:
Line graph
Explanation:
I did it on Study Island
Radioisotopes are substances that are radioactive and have atoms with an unstable nucleus. The data about the radioisotope can be best organized in a line graph. Thus, option B is correct.
What is a graph?A graph is a tool used to represent the data that contains the numerical data and includes the vertices and points to show the numbers and information in a statistical way. It is used to represent the variables of the tables in an easy and understandable manner.
Graphs can be bars, points, lines, columns, bubbles, areas, pie charts, etc. The line graphs use lines to connect the individual variables and are used to track the changes in radioactive material over a time period. It can easily represent the half-life and the remaining time of the radioactive decay.
Therefore, option B. a line graph will be best to represent the information.
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A researcher is measuring changes in the density of the upper atmosphere over time. Which units should be used for the density measurements?
Answer:
grams per liter ≈ g/L
Explanation:
The standard unit of measurement otherwise referred to as SI unit is used in describing various measurement or quantity of value.
However, Density, which is a term that describes the measurement of a substance mass per volume. It is measured using grams per cubic centimeter ≈ g/cm3 when it comes to solids and liquids densities and grams per liter ≈ g/L for gases.
Hence, in this case, since the substance of measurement is atmosphere and it is gaseous in nature, then the correct answer is grams per liter ≈ g/L.
Simulated Vinegar One way to make vinegar (not the preferred way) is to prepare a solution of acetic acid, the sole acid component of vinegar, at the proper pH (see Fig. 2-15) and add appropriate flavoring agents. Acetic acid (Mr 60) is a liquid at 25 °C, with a density of 1.049 g/mL. Calculate the volume that must be added to distilled water to make 1 L of simulated vinegar (see Fig. 2-16).
Answer:
Explanation:
Well, to make it simple, you want to make a solution of acetic acid with pH of 3 using pure acetic acid. We have the dissociation K which makes the life easier:
CH3COOH <--> CH3COO- + H+
k= [CH3COO-]*[H+]/[CH3COOH]
In the target solution [H+]=[CH3COO-]=10^-3. (Based upon pH=-log[H+])
So, all we have to know is how many starting mols of acetic acid (x) can end up with this concentration of H+.
At equilibrium and using the K you've mentioned we can write:
(10^-3)*(10^-3)/(X-10^-3)=1.74*10^-5
(Remeber that if we have a 10^-3 mol concentration of [H+], it means that 10^-3 mol of our starting acid has already dissociated to make it, hence that X-10^-3 instead of a sole X)
If we solve the above equation, we will see that X (the strarting concentration of acetic acid) is about 0.058 mol/lit. Now life gets even easier:
If a mol of acid acetic weights 60 gr, then 0.058 mols should weight... let me see... yes, 3.48 gr... And now, we have the weight, and all we need to calculate the volume, is the density (density=weight/volume), and fortunately, we have that piece of information as well... With a density of 1.049 g/ml, to have 3.49 gr of acid at hand we need to take 3.317 ml of acetic acid which can be rounded to 3.32 ml which you mentioned as the answer!
All that is left to find is that "appropriate flavouring agent" which in my opinion will eventually pose the main problem! (An ester will probably do it...)
What is true and false
For each statement below, write true or false.
16. The mass of an object can vary with the object's location.
17. A mass measurement includes the effect of Earth's gravitational pull on the object
being measured.
18. Scientists measure the amount of matter in terms of mass.
19. Subtle differences in weight exist at different locations on Earth.
20. Your mass on the Moon would be smaller than your mass on Earth.
Answer:
16. false (mass always stays the same)
17. false (that's weight)
18. true
19. true (I think)
20. false (same as 16 and 17)
hope I could help
True and false for each statement is:
16. false
17. false
18. true
19. true
20. false
What is mass?Mass is the quantity of matter. It calculates the inertia of the body. It essentially refers to a body of matter's resistance to changing its speed or location in response to the application of a force. The change caused by an applied force is smaller the more mass a body has.
The mass of a body is the same everywhere, but the weight changes in different places due to gravity. The force of gravity is different in different places, so the weight changes.
That's, why the mass measurement does not include the effect of Earth's gravitational pull on the object. It's the weight.
Thus, the correct options are 16. false, 17. false, 18. true, 19. true, and 20. false.
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Hellpppppp pls it’s due in less than 10 min
Answer:
Theory
Explanation:
the model of an atom, for example isnt a method, its showing a theory in which scientists have discovered and analyze particles, such as atoms. Therefore it is a theory, something that is a known fact
hope this helped:)
Express the following number using scientific notation 5,610,000??
volume measures from other liquids help meh solve the purple pipette but read the directions firsts
Answer:
liquids
Explanation:
are not solids
big brain answer
