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
IRINA_888 [86]
3 years ago
13

When helium was discovered by humans?

Chemistry
1 answer:
saul85 [17]3 years ago
8 0
Helium was discovered in 1868.
You might be interested in
1 What is the approximate mass of a proton?<br> (1)1 u (3) l g<br> (2) 0.0005 u (4) 0.0005 g
joja [24]
Proton mass = 1.672 x 10^-27 kilo. So the approximate mass of a proton would be 1 g or kg.
8 0
3 years ago
What is the mass in 0.25 mol of SO2
gulaghasi [49]

0.25 mols SO₂ x 64.058 g SO₂/ 1 mol SO₂ = 16.0145 g SO₂

molar mass of SO₂: 64.058 g

answer: 16 grams of SO₂ (2 sig figs)

check the question to see if its asked for a specific unit for mass (grams or kilograms, if they asked for kiligrams then convert 16 grams to kilograms by dividing it by 1000)


5 0
3 years ago
The atmosphere is a(n) _____. <br> 1. element <br> 2. compound <br> 3. mixture
tensa zangetsu [6.8K]
The atmosphere is a mixture of gasses.
5 0
3 years ago
Read 2 more answers
Which material is not a metamorphic rock
ASHA 777 [7]
Letter C would be the correct answer
3 0
3 years ago
Please help me with this question!! I’m not sure if they’re the insoluble ions that precipitate with chromate or the soluble one
Vika [28.1K]

Answer:

2) Copper (II) Chloride

Explanation:

A precipitate will form if the resulting compound is insoluble in water. For example, a silver nitrate solution (AgNO3) is mixed with a solution of magnesium bromide (MgBr2).

4 0
3 years ago
Other questions:
  • How sig figs are in 28.0
    12·2 answers
  • Identify each energy exchange as primarily heat or work and determine whether the sign of δe is positive or negative for the sys
    10·2 answers
  • Which substance is oxidized and which is reduced in this reaction?
    14·1 answer
  • 10.0 g of Mg(NO3)2 = ____ moles
    13·1 answer
  • The H30+ concentration of a solution is equal to 0.8 M. What is the pH of the solution?
    7·1 answer
  • What are molecules and what are they made of?
    13·1 answer
  • Is C2H2 + 2H2 ----- C2H6 a substitution reaction​
    15·1 answer
  • Electromagnetic waves are used in many technological devices. Describe two examples of how energy from electromagnetic waves is
    8·1 answer
  • Who wants to talk till 1am? hmu:)
    12·1 answer
  • A 400. 0 g sample of liquid water is at 30. 0 ºc. how many joules of energy are required to raise the temperature of the water t
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!