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
padilas [110]
3 years ago
11

What was discovered first helium or samarium?

Chemistry
1 answer:
lana [24]3 years ago
7 0
The correct answer is helium, but both discoveries were quite close. Helium was discovered in 1868 during a solar eclipse by French astronomer Jules Janssen, while samarium was discovered in 1879 by a French chemist Paul Émile Lecoq de Boisbaudran.
You might be interested in
What are THREE reasons that a creature might use MIMICRY
8_murik_8 [283]

Answer:

- hide from predators

- in search of food

- shelter and protection

thenks and mark me brainliestt :))

7 0
3 years ago
I need help asap <br>why is there only one variable in an experiment that changes? ​
tekilochka [14]

Answer: If more than one variable is changed in an experiment, scientist cannot attribute the changes or differences in the results to one cause. By looking at and changing one variable at a time, the results can be directly attributed to the independent variable.

5 0
2 years ago
8. An atom has 9 protons, which element is it?​
ValentinkaMS [17]

Answer:

fluorine

Explanation:

The element fluorine has 9 protons and 9 electrons.

3 0
3 years ago
Read 2 more answers
8). How many moles of oxygen gas must be placed in a 35.0 L container in order
klemol [59]

Answer:

4.1 moles

Explanation:

Applying

PV = nRT................ equation 1

Where P = pressure, V = volume, n = number of moles, R = molar gas constant, T = Temperature.

make n the subject  of the equation

n = PV/RT.............. Equation 2

From the question,

Given: V = 35 L , P = 2.8 atm, T = 15 °C  = (15+273) = 288 K, R = 0.083 L.atm/K.mol

Substitute these values into equation 2

n = (35×2.8)/(0.083×288)

n = 4.1 moles

5 0
3 years ago
A student dissolves of glucose in of a solvent with a density of . The student notices that the volume of the solvent does not c
nikitadnepr [17]

Answer:

0.052 M

0.059 m

Explanation:

There is some missing info. I think this is the complete question.

<em>A student dissolves 4.6 g of glucose in 500 mL of a solvent with a density of 0.87 g/mL. The student notices that the volume of the solvent does not change when the glucose dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to 2 significant digits.</em>

Step 1: Calculate the moles of glucose (solute)

The molar mass of glucose is 180.16 g/mol.

4.6 g × 1 mol/180.16 g = 0.026 mol

Step 2: Calculate the molarity of the solution

0.026 moles of glucose are dissolved in 500 mL (0.500 L) of solution. We will use the definition of molarity.

M = moles of solute / liters of solution

M = 0.026 mol / 0.500 L = 0.052 M

Step 3: Calculate the mass corresponding to 500 mL of the solvent

The solvent has a density of 0.87 g/mL.

500 mL × 0.87 g/mL = 435 g = 0.44 kg

Step 4: Calculate the molality of the solution

We will use the definition of molality.

m = moles of solute / kilograms of solvent

m = 0.026 mol / 0.44 kg = 0.059 m

4 0
3 years ago
Other questions:
  • Use the graph to determine which is greater, the heat of fusion or the heat of vaporization. Explain how you used the graph to d
    6·1 answer
  • Is wood a compound, element or mixture
    6·2 answers
  • In which process does a solid change directly into a vapor?
    9·1 answer
  • CAN SOMEONE HELP ME ON SCIENCE?!!! I NEED HELP. ITS JUST TRUE OR FALSE. I DONT UNDERSTAND. PLZ HELP ME!! TODAY. 1-6. I AINT CHEA
    9·1 answer
  • How are the IUPAC molecular naming system and the zoological taxonomic naming system similar and how are they different?
    6·2 answers
  • Which of the following would most likely cause rising air
    12·1 answer
  • Which electrons in a calcium atom in the ground state have the greatest effect on the chemical properties of calcium
    6·2 answers
  • Two identical 732.0 L tanks each contain 212.0 g of gas at 293 K, with neon in one tank and nitrogen in the other. Based on the
    12·1 answer
  • Which sphere protects Earth’s surface?<br><br> atmosphere<br> biosphere<br> geosphere<br> hydrosphe
    12·2 answers
  • Dentify the reagents used to carry out the chlorination of benzene. a. cl2/ccl4 b. cl2/fecl3 c. cl2/nacl d. both b and c e. a, b
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!