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
oksian1 [2.3K]
2 years ago
11

Element X has two isotopes. If 72.0% of the element has an isotope mass of 84.9 atomic mass units, and 28.0% of the element has

an isotopic mass of 87.0 atomic mass units, the average atomic mass of element X is numerically equal to
Chemistry
1 answer:
bija089 [108]2 years ago
8 0
<h2>Answer:</h2>

Average atomic mass of an element is the sum of the masses of its isotopes each multiplied by its natural abundance

\footnotesize \longrightarrow \:  \rm Average \:  atomic  \: mass =  \dfrac{ \sum\limits \: \% age \: of \: each \: isotope \times Atomic  \: mass }{100} \\

\footnotesize \longrightarrow \:  \rm Average \:  atomic  \: mass =  \dfrac{ 72 \times84.9 + 28 \times 87  }{100} \\

\footnotesize \longrightarrow \:  \rm Average \:  atomic  \: mass =  \dfrac{ 6112.8 + 2436  }{100} \\

\footnotesize \longrightarrow \:  \rm Average \:  atomic  \: mass =  \dfrac{ 8548.8  }{100} \\

\footnotesize \longrightarrow \:  \bf Average \:  atomic  \: mass =  85.488 \: amu  \\

You might be interested in
How much heat is evolved in converting 1.00 mol of steam at 155.0 ∘c to ice at -50.0 ∘c? the heat capacity of steam is 2.01 j/(g
Ne4ueva [31]
When the specific heat capacity of the water is 4.18 J/g.°C so, we are going to use this formula to get the heat for cooling three  phases changes from steam to liquid and from liquid to ice (solid) :

when Q = M*C*ΔT 

Q is the heat in J

and M is the mass in gram = 1 mol H2O * 18 g/mol(molar mass) = 18 g

C is the specific heat J/g.°C

ΔT is the change in temperature

Q = Mw *[ ( Csteam * ΔTsteam)+(Cw*ΔTw) + (Cice  * ΔT ice)]

    = 18 g * [(2.01 * (155-100°C)) + (4.18 * (100-0°C)) + (2.09 * (0 - 55 °C))]

∴Q = 7444.8 J

and when we know that the heat of fusion for water = 334J/g

and heat of vaporization for water =  2260J/g


∴Q for the two phases changes = M * (2260+334) 

                                                      = 18 * (2260+334)

                                                      = 46692 J 

∴ Q total = 7444.8 + 46692 = 54136.8 J
5 0
3 years ago
If 200 g of water is heated from 20 C to 40 C, then what is the heat added in kilocalories (same as food calories)?
Maslowich

Answer: 4Kcal

Explanation:

H= mcø

M=200g

C= 1 cal/g/°c

Ø= 40-20=20°c

H= 200*1*20= 4000calories= 4Kcal

8 0
2 years ago
Which molecule below has hydrogen bonding? Which molecule below has hydrogen bonding? H2 CH3CH2OH HCl CH4 all of the above
QveST [7]

Answer:

CH_3CH_2OH

Explanation:

Hydrogen bonding:-

Hydrogen bonding is a special type of the dipole-dipole interaction and it occurs between hydrogen atom that is bonded to highly electronegative atom which is either fluorine, oxygen or nitrogen atom.

Partially positive end of the hydrogen atom is attracted to partially negative end of these atoms which is present in another molecule. It is strong force of attraction between the molecules.

Thus, hydrogen must be linked to electronegative atom which is oxygen, fluorine and nitrogen which is in CH_3CH_2OH and thus, it will shown hydrogen bonding.

3 0
2 years ago
In terms of energy what kind of system is a sealed glass terrarium on a windsill?
Snezhnost [94]
If the sealed glass is permeable to sunlight or to transfer of heat will be an open system, but if the sealed glass is a thermic glass and doesn't allow exchange of heat and exchange of solar energy (for example a mirrored glass that reflect the sunlight) and the terrarium is not exchanging energy with the surroundings will be a closed system. It is a question that doesn't specify too many details about the system in the study. It is hard to give a final answer without making some assumptions.
6 0
3 years ago
Read 2 more answers
What is the universe made of? Astronomers face an embarrassing conundrum: they don't know what 95% of the universe is made of.
Citrus2011 [14]

Answer:

I think u understand this answers

4 0
3 years ago
Other questions:
  • Which substance is most likely to heat up the fastest?
    6·2 answers
  • The direction of gas movement is determined by ______________. solubility of the gas in blood size of the gas molecule temperatu
    8·1 answer
  • A chemist has 12 liters of a 25% acid solution. how many liters of water must be added to obtain a 20% acid solution?
    12·1 answer
  • If you are using 3.00% (mass/mass) hydrogen peroxide solution and you determine that the mass of solution required to reach the
    9·1 answer
  • Which compound has the lowest melting point?<br> • CuO<br> • C6H12O6<br> K2Cr2O7<br> • BaCl2
    13·1 answer
  • How are strong acids and strong bases similar?
    13·1 answer
  • The theory of evolution states
    14·1 answer
  • PLEASEEEE ANSWERR 15 POUNTS
    9·2 answers
  • How many liters of oxygen (at STP) are required to form 10.5 grams of hydrogen
    5·1 answer
  • Lab Report
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!