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
Bumek [7]
3 years ago
6

What element has a mass number of 138 and protons equal to 57?

Chemistry
2 answers:
goblinko [34]3 years ago
7 0
Lanthanum  is your answer i believe.
~ thank you for letting me answer your question here on brainly! much love from england xx
Murljashka [212]3 years ago
6 0


Basic Information
Name:<span> Lanthanum </span>
Symbol:<span> La </span>
Atomic Number:<span> 57 </span>
Atomic Mass:<span> 138.9055 amu </span>
Melting Point:<span> 920.0 °C (1193.15 K, 1688.0 °F) </span>
Boiling Point:<span> 3469.0 °C (3742.15 K, 6276.2 °F) </span>
Number of Protons/Electrons:<span> 57 </span>
Number of Neutrons:<span> 82 </span>
Classification: Rare Earth 
Crystal Structure:<span> Hexagonal </span>
Density @ 293 K:<span> 6.7 g/cm</span>3 
Color:<span> white

</span>
You might be interested in
Write the chemical formula for a molecule of non cyclic amp.
RSB [31]
The structural formula shown in the picture is the cyclic AMP or cyclic adenosine monophosphate. It is an essential component in RNA synthesis and metabolic processes. When it becomes non-cyclic after enzymatic reaction, you would have to disconnect the cyclic rings. When you do, you add 2 H atoms, one for each terminal end. The formula for cyclic AMP is C₁₀H₁₄N₅O₇P. Since there are three cyclic rings, you would have to add 6 hydrogen atoms. Thus, the formula for noncylic AMP is C₁₀H₂₀N₅O₇P.

6 0
2 years ago
PPPPPPPLLLLLLLLZZZZZZ HELP I'LL GIVE BRAINLIEST
Alex17521 [72]

Food web should be the correct answer

:)


7 0
3 years ago
Read 2 more answers
The elements helium,neon,and xenon are all part of the same __________ on the periodic table.
Irina18 [472]
They are all part of the same group which is Group 18, otherwise known as the Noble Gases
8 0
2 years ago
Read 2 more answers
This element has 3 electrons in its Lewis dot structure and is in the 2p orbital section
Ulleksa [173]
Hen two electrons occupy the same orbital, they always have opposite spin. No other knowledge about electron spin is needed for A-level.) Only when the 2s is filled, can the 2p sub-level fill. With the next six elements (boron, carbon, nitrogen, oxygen, fluorine and neon) the three 2p orbitals are filled.
3 0
3 years ago
What is the balanced equation for combustion of dicarbon hexahydride
Harman [31]
Complete combustion

2C2H6 + 7O2 = 6H2O + 4CO2

7 0
3 years ago
Other questions:
  •  
    7·2 answers
  • What is formed from joining<br> positive and<br> negative ions
    14·1 answer
  • A chemical reaction that absorbs energy in the form of heat is described as
    11·2 answers
  • For the following systems at equilibrium C: CaCO3(s) ⇌ CaO(s)+CO2(g) ΔH=+178 kJ/mol D: PCl3(g)+Cl2(g) ⇌ PCl5(g) ΔH=−88 kJ/mol cl
    5·1 answer
  • An air mattress is filled with 16.5 moles of air. The air inside the mattress has a temperature of 295 K and a gauge pressure of
    9·2 answers
  • An aqueous solution of ammonia is found to be basic. This observation can be explained by the net ionic equationHNO3(aq) + H2O(l
    10·1 answer
  • In terms of energy, when atoms chemically bond to form a stable compound:_____.
    13·1 answer
  • Balance FeCl3 + MgO ---&gt; Fe2O3 + MgCl2
    12·1 answer
  • 4. How can you calculate the solubility of a gas in a liquid under different<br> pressures
    10·1 answer
  • Which of the following animals are an example of coevolution? *
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!