1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Dahasolnce [82]
3 years ago
6

Which is a good example of a contact force? A. protons in the nucleus of an atom B. a ball falling down after it's thrown up int

o the air C. a satellite orbiting Earth D. a bat hitting a ball
Chemistry
1 answer:
Vesnalui [34]3 years ago
8 0

Answer:

B

Explanation:

Because a ball falling down is a good strong force

You might be interested in
rank the four gases (air, exhaled air, gas produced from the decomposition of H2O2, gas from decomposition of NaHCO3, in order o
SVEN [57.7K]

Answer: H₂O₂ (94%) > Air (23%) > Exhaled air (13%) > NaHCO₃ (0%)


Initial important note:


Although NaHCO₃ contents oxygen atoms, and you can calculate its compositoin, the resulting gas does not containg pure oxygen gas (O₂). For the comparisson it is not useful to calculate the content of oxygent atoms, but the concentration of O₂ gas. As such, the gas from NaHCO₃ contains 0% of pure O₂, that is why it is ranked last.


1) Air:


Source: internet


Approximate 23%. It is variable, because air is not a pure substance but a mixture of gases, whose compositon is not unique.


2) Exhaled air:


Source: internet.


Approximate 13%. The compositon of the air changes in our lungs, due to the respiration process: we inhale fresh air with around 23% of oxygen, part of this oxygen pass to the cells (lungs - blood - heart - cells) and then it is exhaled with a lower content of air and a greater content of CO₂


3) Air from the decomposition of H₂O₂.


In this case we can do a chemical calculation, since we can state the chemical equation of the reaction:


i) Chemical Equation:


H₂O₂ (g) → H₂ (g) + O₂ (g)


ii) mole ratio of the products 1 mol H₂ : 1 mol O₂


iii) convert moles into mass (grams)


1 mol H₂ × 2 × 1.008 g/mol = 2.016 g


1 mol O₂ × 2 × 15.999 g/mol = 31.998 g


Composition, % = [31.998 g / (2.016 g + 31.998 g) ] × 100 ≈ 94%



4) Air from the decomposition of NaHCO₃:


i) chemical equation:


2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)


ii) mole ratio: take into account only the gases in the products:


1 mol CO₂ (g) : 1 mol H₂O


iii) mass in grams


CO₂: molar mass ia approximately 44.01 g/mol


H₂O: molar mass is approximately 18.02 g/mol


iii) Those gases although have oxygen atoms, do not hae free oxygen gas, which is what we are compariing. That means, that from the decomposition of NaHCO₃ you get 0% oxygen gas.


5) The result is:


H₂O₂ (94%) > Air (23%) > Exhaled air (13%) > NaHCO₃ (0%)

7 0
3 years ago
Read 2 more answers
1. Leigh is preparing popcorn for her friends. She removes a stick of butter from the refrigerator and cuts a fourth of it from
Ksivusya [100]
Well your mass wont change...so it would be 35 grams of a liquid

6 0
3 years ago
Read 2 more answers
Stock naming please help
andre [41]

Answer:

Can you tell me the question in the comments on this answer or like how you do it then ill answer you in the comments under this answer

8 0
3 years ago
How many joules of heat is lost when a 64 g piece of copper cools from 375 oC to 26 oC? The specific heat of copper is 0.38 J/go
Svetlanka [38]

Answer: 8500 J lost or -8500 J

Explanation:

q=cmt

t=375-26

t=349

q=0.38(64)(349)

q=8487.68 J

Answer must have 2 sig figs, which means it rounds to 8500 J.

7 0
3 years ago
The decomposition of acetaldehyde is a second order reaction with a rate constant of 4.71 10−8 L/mol/s. What is the instantaneou
pochemuha

Answer: Rate of decomposition of acetaldehyde in a solution is 1.45\times 10^{-14}mol/Ls

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

For a reaction : A\rightarrow products

Rate=k[A]^x

k= rate constant

x = order of the reaction = 2

Rate=4.71\times 10^{-8}L/mol/s\times {5.55\times 10^{-4}M}^2

Rate=1.45\times 10^{-14}

Thus rate of decomposition of acetaldehyde in a solution is 1.45\times 10^{-14}mol/Ls

6 0
3 years ago
Other questions:
  • When hydrochloric acid reacts with sodium sulfide, hydrogen sulfide gas and sodium chloride are produced. How many moles of H2S
    13·1 answer
  • What is the [OH-] of solution with pH of 3.4?
    8·2 answers
  • What is a type of air mass that forms over oceans?
    12·2 answers
  • The [H+] of a solution can be determined from the pH using the equation: [H+] = 10 - pH ... Where: [H+] = hydrogen ion concentra
    12·1 answer
  • When atoms combine they form<br> A. molecules<br> B.periodic table<br> C.particles<br> D.protons
    12·1 answer
  • Why do atomic models change over time
    14·1 answer
  • What is the percentage of nitrogen in the fertilizer urea ((nh2) 2co)
    13·1 answer
  • Which chemical can remove color of red/Pink phenol and make it clear like water transparent?
    12·2 answers
  • ANYONE PLEASE HELP BY THURSDAY!!
    6·1 answer
  • Please help! Is there another way that 3.40x10^-19J can be imputed on a computer. I have the right answer but it is wrong.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!