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
stealth61 [152]
3 years ago
11

Any science fair questions for 8th graders? please list at least 4

Chemistry
1 answer:
TEA [102]3 years ago
6 0

How does water purity affect surface tension?

When is the best time to plant soy beans?

Which material is the best insulator?

How does arch curvature affect load carrying strength?

How do different foundations stand up to earthquakes?

What sugars do yeast use?

You might be interested in
Before it was launched, a helium-filled balloon had a pressure of 101 kPa at a temperature of 20°C. At an altitude of 15 000 m,
bogdanovich [222]

Answer:

5.54 m³.

Explanation:

  • We should use the ideal gas law: <em>PV = nRT,</em>

where, P is the pressure of the gas in atm,

V is the volume of the gas in L,

n is the number of moles in mole,

R is the general gas constant (R = 0.082 L.atm/mol),

T is the temperature of the gas in K.

<em>We have two different cases at different (P, V and T) while the number of moles of He and R is constants.</em>

<em>∴ (P₁V₁) / (T₁) = (P₂V₂) / (T₂).</em>

We can use P in KPa and V in m³ that the conversion factor can be canceled by division, but we should use T in K because its conversion factor is additive value.

P₁ = 101.0 kPa, V₁ = <em>??? m³</em>, and T₁ = (20 °C + 273) = 293.0 K.

P₂ = 11.7 kPa, V₂ = 35.4 m³, and T₂ = (-56 °C + 273) = 217 K.

∴ The initial volume (V₁) = (P₂V₂T₁) / (P₁T₂) = (11.7 kPa)(35.4 m³)(293.0 K) / (101.0 kPa)(217.0 K) = (121354.74) / (21917) = 5.537 m³ ≅ 5.54 m³.

7 0
3 years ago
Which of the following is NOT a part of cell theory?
astraxan [27]

Answer:

What is the following?

Explanation:

I think I can answer this, I recognize the question

6 0
3 years ago
Read 2 more answers
What is a limiting reagent?
prisoha [69]
It is the substance that is totally consumed when the chemical reaction is complete.
3 0
4 years ago
Studying the decay of radioactive isotopes in dead organisms helps scientists to identify fossilized remains. The ratio of C-12
satela [25.4K]

Answer:

Only Organism Z is alive, and Organism X has been dead longer than Organism Y.

Explanation:

After the death of an organism, there is radioactive disintegration of C-14 allotrope of carbon, which increases the ratio of C-12 to C-14 in a dead organism as compared to a living organism.

7 0
3 years ago
A fast-moving neutron strikes a U235 nucleus. The nucleus shatters producing Sm155, Zn78, and three neutrons. Describe this chan
Natasha2012 [34]

The balanced nuclear equation for the reaction is

<h3>²³⁵₉₂U + ¹₀n —> ¹⁵⁵₆₂Sm +  ⁷⁸₃₀Zn + 3(¹₀n)</h3>

From the question given above, we were told that:

<u>A fast-moving neutron strikes a ²³⁵U nucleus. The nucleus shatters producing ¹⁵⁵Sm, ⁷⁸Zn, and three neutrons.</u>

The nuclear equation can be written as follow:

Neutron => ¹₀n

Uranium => ²³⁵₉₂U

Samarium => ¹⁵⁵₆₂Sm

Zinc => ⁷⁸₃₀Zn

Uranium + neutron —> Samarium + Zinc + 3 moles of neutron

<h3>²³⁵₉₂U + ¹₀n —> ¹⁵⁵₆₂Sm +  ⁷⁸₃₀Zn + 3(¹₀n)</h3>

 

 The nuclear equation above is balanced.

Learn more: brainly.com/question/9943790

3 0
3 years ago
Other questions:
  • Why is matter measured in mass and not weight?​
    5·2 answers
  • Complete the passage to Distinguish between mechanical and electromagnetic waves.
    14·1 answer
  • HELP!!!!!<br> i need help on this chemistry question
    8·1 answer
  • Proper name of baking soda
    6·1 answer
  • What kind of group 1 atoms are the most reactive? a. Small atoms c. Atoms with the most electrons in the valence level b. Large
    8·2 answers
  • Could someone help me out with these questions???
    12·2 answers
  • B. Hot water
    15·1 answer
  • How does the body react when the outside temperature gets too hot
    11·1 answer
  • How many grams of sodium are in 10g. of aodium sulfate
    15·2 answers
  • List 10 concepts/words associated with motion​​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!