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
Harrizon [31]
2 years ago
12

What was helium used for in the past?

Chemistry
2 answers:
yawa3891 [41]2 years ago
6 0
Helium used to be used in hot air balloons.  Then, when the Hindenburg exploded, annexed file, they realized that hydrogen was not only lighter, but it also was less flammable.  

Otrada [13]2 years ago
3 0

Hot air balloons. They have a little hot plate/fire or whatever and they used, and that made the helium rise, thus rising the balloon.
You might be interested in
 Consider a bathtub filled with water, with a plug in the drain. How long would this be considered a closed system?
Monica [59]
For a closed system, you need two things:
1) a conservation of mass within the boundaries of the system
2) the ability to freely exchange energy to & from the "closed" system with a surrounding external system


So, the answer is <u><em>never</em></u>, since your defining the "system" as the water within the bathtub, and an open bathtub is exposed to evaporation, which is not conserving mass within the defined "system".
8 0
3 years ago
Read 2 more answers
A sample of 8.11 g 8.11 g of solid calcium hydroxide is added to 38.0 mL 38.0 mL of 0.410 M 0.410 M aqueous hydrochloric acid. W
Andrews [41]

Answer:

The balanced chemical equation :

Ca(OH)_2(s)+2HCl(aq)\rightarrow CaCl_2(aq)+2H_2O(l)

Explanation:

When calcium hydroxide reacts with hydrochloric acid it gives calcium chloride and water as a products. The chemical equation is given as:

Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O

According to question, solid calcium hydroxde is added to 38.0 mL of 0.410 M of HCl solution, so the chemical equation can be written as:

Ca(OH)_2(s)+2HCl(aq)\rightarrow CaCl_2(aq)+2H_2O(l)

According to stoichiometry, when 1 mole of solid calcium hydroxide reacts with 1 mole of hydrochloric acid to gives 1 mole of aqueous calcium chloride and 1 mole of water.

4 0
3 years ago
Metals and nonmetals all lesson explanation for class 8​
WINSTONCH [101]

Answer:

Metalloids elements whose properties are intermediate between those of metals and solid nonmetals or semiconductors.

Some examples:

Chemical element.

Boron.

Semiconductor.

Arsenic.

Silicon.

Selenium.

Antimony.

Germanium.

7 0
3 years ago
What caused the temperature of the sand to change?
Setler79 [48]
Sand is usually hot from the sun. It is hot because of the sun. if the sand were to be wet then it would take longer to change.
8 0
3 years ago
Read 2 more answers
For centuries, sailors used tree sap (pitch) to seal the spaces between the planks on wooden boats. Explain why pitch worked wel
o-na [289]
Tree sap is a viscoelastic polymer, which means it's not really a solid but a very viscous (sticky) fluid. It's fluidity ensures that it can properly <span>seal the spaces between the planks on wooden boats. Not only that, the pitch sap is hydrophobic - it is water resistant as well. </span>
5 0
3 years ago
Other questions:
  • Determine the chemical formulas for the two compounds below. (Carbon, Hydrogen, and Oxygen).
    8·1 answer
  • Rate at which a chemical substance tends to undergo a chemical reaction
    13·2 answers
  • Suppose that 0.48 g of water at 25∘C∘C condenses on the surface of a 55-gg block of aluminum that is initially at 25∘C∘C. If the
    5·1 answer
  • Tellurium is a period 5 chalcogen. Selenium is a period 4 chalcogen. If the only factor affecting ionization energies was the nu
    15·1 answer
  • Which group has different numbers of valence electrons
    7·1 answer
  • How do the densities of the two objects compare?
    5·1 answer
  • Between Na and Na+ which has larger size​
    13·1 answer
  • 1. _____ represents a formula for a chemical compound.<br> A.H<br> B.C<br> C.P<br> D.H2O
    14·2 answers
  • Consider the following electron configurations to answer the questions that follow: (i) 1s2 2s2 2p6 3s1 (ii) 1s2 2s2 2p6 3s2 (ii
    12·1 answer
  • Panuto: Punan ang talaan sa ibaba at suriing mabuti ang sarili upang higit mong
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!