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Harrizon [31]
3 years ago
12

What was helium used for in the past?

Chemistry
2 answers:
yawa3891 [41]3 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]3 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.
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Which property is NOT used to separate a mixture?
NeTakaya

Answer: ability to undergo a chemical reaction

Explanation:

6 0
3 years ago
What is the formal charge on the hydrogen atom in hbr? use the periodic table as needed?
Westkost [7]
A covalent bond is formed between H and Br
The structure of HBr is as follows
H —Br
Formal charge for atoms are the charges for individual atoms in compounds.
Formal charge can be calculated as follows ;
Formal charge of atom = number of valence electrons -( number of bonds + number of lone pair electrons)
H has 1 valence electron, 1 bond and 0 number of lone pair electrons
Formal charge of H = 1 -1 -0 = 0
H has 0 charge
3 0
3 years ago
What do elements in the same group in the periodic table have in common
Shalnov [3]

Answer:

The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.

Explanation:

8 0
2 years ago
What is the balanced net ionic equation including phases for K2SO4 and SrI2
Triss [41]

Answer:

Sr 2+(aq) + SO42-(aq) → SrSO4(s)

Explanation:

<u>Step 1</u>: Write a properly balanced equation with states:

K2SO4(aq) + Srl2(aq) → 2KI(aq) + SrSO4(s)

<u>Step 2</u>: write the full ionic equation with states. Remember to keep molecules intact. Only states (aq) will dissociate,  (s) will not dissociate . This means SrSO4 won't dissociate.

2K+(aq) + SO42-(aq) + Sr 2+(aq) + 2I-(aq) → 2K+(aq) + 2I-(aq) + SrSO4(s)

<u>Step 3</u>: Balanced net ionic equation

Sr 2+(aq) + SO42-(aq) → SrSO4(s)

3 0
3 years ago
(a) Show that the pressure exerted by a fluid P (in pascals) is given by P = hdg, where h is the column of the fluid in metres,
Komok [63]

Answer:

B) THE DEPTH OF THE LAKE IS 0.060 m

Explanation:

b) Determine the depth of the lake in metres

1. Using the general gas law, we will calculate the initial pressure of the air bubbles.

P1V1 /T1 = P2V2/T2

P1 = Unknown

T1 = 5.24 °C

T2 = 18.73 °C

P2 = 0.973 atm

V1 = V1

V2 = 6V1

P1 = P2 V2 T1 / V1 T2

P1 = 0.973 * 6V1 * 5.24 / V1 * 18.73

P1 = 5.09852 * 6 / 18.73

P1 = 30.59112 / 18.73

P1 = 1.633 atm.

2. Calculate the depth of the lake:

             Pressure = length * density * acceleration

            length = Pressure / density * acceleration

Pressure = 1.633 atm = 1.633 * 101, 325 Nm^2 = 165, 463.725 Nm^2

Density =  1.02 g/cm3 = 1.02 * 10^3 kg/m^3

Acceleration = 9.8 m/s^2

So therefore, the length in metres is:

Length = density * acceleration / pressure

Length =  1.02 *10^3 * 9.8 / 165, 463.725  

Length = 9.996 * 10^3 / 165 463.725

Length = 0.06 m

Hence, the depth of the lake is 0.06 m

6 0
3 years ago
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