(Please Help)
1.What is the most common isotope for element X
2.Calculate the average atomic mass or element X
Answers
Answer:
1. Isotope 2 occurs most commonly
2. 39.02amu
Explanation:
1. Isotope 2 has a relative abundance of 78.68% i.e. 78.68 out of 100, hence, it is the isotope that occurs most commonly.
2. Isotope 1 = 9.67%, mass no: 38
Isotope 2 = 78.68%, mass no: 39
Isotope 3 = 11.34%, mass no: 40
Isotope 4 = 0.31%, mass no: 41
To find the average atomic mass of element X, we multiply each isotopes' relative abundance by its mass no and find the sum as follows:
We convert each percentage to decimal abundance:
Isotope 1 = 9.67% = 0.0967
Isotope 2 = 78.68% = 0.7868
Isotope 3 = 11.34% = 0.1134
Isotope 4 = 0.31% = 0.0031
(0.0967 × 38) + (0.7868 × 39) + (0.1134 × 40) + (0.0031 × 41)
3.6746 + 30.6852 + 4.536 + 0.1271
Average atomic mass = 39.02amu
Related Questions
need help asap!!!
so i don’t necessarily need an answer just how to solve everything.
this is the first one:
calcium hydroxide + ammonium chloride
the instructions are attached to this question. i’m just not sure how to do everything. it doesn’t give me the products side only the reactants so how am i supposed to write and balance the equation?
Answers
Explanation:
とおふぉくぉをえおろとようおいおぽあおそ・
'」*とまっぉのもヴぉこぉぞぽ、こ、
Answer:
Ca(OH)2 + 2NH4Cl .................. CaCl2 + 2NH3 + 2H2O
Determine the enthalpy for the reaction A+B --> C If we know the following:
A+E --> C+D; delta H = -200 kJ
D+B --> E; delta H = -100 kJ
Answers
Explanation:
here is the answer to the question
Cuál es el cruce para un niño donde su padre tiene el pelo rizo RR y su madre pelo lacio rr
Answers
Answer:
Rr
Explanation:
What are the example of molecule ?
Answers
Explanation:
H2O water molecule
O3 Ozone
are some of common example of molecules
If the sky is actually black, and the water is actually clear, where does the blue color for the sky and water come from?
Answers
Answer:
that the water is blue because of the way water absorbs light, the way particles in the water scatter light, and also because some of the blue light from the sky is reflected
Polywool fibre is
a.natural
b.synthetic
c.monomer
d.blended
Answers
Polywool fibre is synthetic.
⇒b. Synthetic
Hope It Helps You ✌️
Answer:
[tex]\large{\underbrace{\underline{\fcolorbox{White}{pink}{\bf{b.synthetic }}}}}
[/tex]
The first excited state of a particular atom in a gas is 6.1 eV above the ground state. A moving electron collides with one of these atoms, and excites the atom to its first excited state. Immediately after the collision the kinetic energy of the electron is 3.2 eV. What was the kinetic energy of the electron just before the collision
Answers
Answer:
The kinetic energy of the electron just before the collision is 9.3 eV.
Explanation:
We can find the kinetic energy of the electron before the collision can be found by energy conservation:
[tex] E_{i} = E_{f} [/tex]
[tex] K_{a_{i}} + K_{e_{i}} = K_{a_{f}} + K_{e_{f}} [/tex] (1)
Where:
[tex]K_{a_{i}}[/tex]: is the initial kinetic energy of the atom
[tex]K_{a_{f}}[/tex]: is the final kinetic energy of the atom = 6.1 eV + [tex]K_{a_{i}}[/tex]
[tex]K_{e_{i}}[/tex]: is the initial kinetic energy of the electron =?
[tex]K_{e_{f}}[/tex]: is the final kinetic energy of the electron = 3.2 eV
By solving equation (1) for [tex]K_{e_{i}}[/tex] we have:
[tex]K_{a_{i}} + K_{e_{i}} = (6.1 eV + K_{a_{i}}) + 3.2 eV[/tex]
[tex] K_{e_{i}} = 6.1 eV + 3.2 eV = 9.3 eV [/tex]
Therefore, the kinetic energy of the electron just before the collision is 9.3 eV.
I hope it helps you!
what is displacement?
Answers
Answer:
the moving of something form it's places or position
In an electrically neutral atom, the number of
protons equals the number of neutrons.
protons equals the number of electrons.
neutrons equals the number of electrons.
A. Protons equals the number of neutrons
B. Protons equal the number of electrons
C. Neutrons equals the number of electrons
Answer: B
Answers
Answer:
B
Explanation:
because protons have a +1 charge and electrons have a -1 charge, so if an atom is neutral it must have the same amount of protons and neutrons
please let me know if this is correct?
Answers
Answer: Yes! you're all good. Alkali metals in group 1 are the most metallic :)
The nonmetals include which of the following groups? Use the periodic table to answer the question. Check all that apply.
halogens
alkali metals
lanthanides
noble gases
alkaline earth metals
Answers
Answer:
En el grupo de los no metales se incluyen los halógenos (flúor, cloro, bromo, yodo, astato y téneso), que tienen 7 electrones en su última capa de valencia y los gases nobles (helio, neón, argón, kriptón, xenón, radón), que tienen 8 electrones en su última capa (excepto el helio, que tiene 2).
Explanation:
halógenos
Answer:
1,4
Explanation:
a beam balance is called a first class lever why?
Answers
Answer:
A beam balance is an example of a first class lever.
Explanation:
A beam balance is an example of a first class lever. In a first class lever, the fulcrum is between the effort (force) and the load. The effort (force) moves over a large distance to move the load a smaller distance.
Other examples of first class lever are pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance etc.
calculate the final pressure of a gas that is expanded from 725cm³ at 30C and 1.19 atm to 1.12cm³ at 43C
Answers
Answer:
Final pressure, P2 = 1088.89 atm
Explanation:
Given the following data;
Initial volume, V1 = 725 cm³
Initial temperature, T1 = 30°C
Initial pressure, P1 = 1.19 atm
Final volume, V2 = 1.12 cm³
Final temperature, T2 = 43°C
To find the final pressure (P2), we would use the combined gas law.
Mathematically, the combined gas law is given by the formula;
[tex] \frac {PV}{T} = k [/tex]
[tex] \frac {P_{1}V_{1}}{T_{1}} = \frac {P_{2}V_{2}}{T_{2}} [/tex]
Substituting into the formula, we have;
[tex] \frac {1.19*715}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] \frac {850.85}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] 28.3617 = \frac {P_{2}*1.12}{43} [/tex]
Cross-multiplying, we have;
[tex] 28.3617 * 43 = 1.12P_{2} [/tex]
[tex] 1219.5531 = 1.12P_{2} [/tex]
[tex] P_{2} = \frac {1219.5531}{1.12} [/tex]
Final pressure, P2 = 1088.89 atm
The mass of a neutron is
Answers
Which of the following statements about the nucleus is false?
A. Contains nearly all of the mass of the atom.
B. Able to be lost or gained in chemical reactions.
C. None of these
D. Made up of protons and neutrons
Answers
Answer:
B. Able to be lost or gained in chemical reactions.
Answer:
B
Explanation:
a chemical reaction would only move the nucleas
If a man reach a 25 km distance in 30 min in his car , find the average velocity
Answers
Answer:
Average velocity of car = 50 km/h
Explanation:
Given information;
Distance cover by man in his car = 25 kilometer
Time taken by man to cover distance = 30 min
Find:
Average velocity of car
Computation:
Time taken by man to cover distance = 30 min
Time taken by man to cover distance = 30 / 60
Time taken by man to cover distance = 0.5 hour
Average velocity = Distance / Time
Average velocity of car = Distance cover by man in his car / Time taken by man to cover distance
Average velocity of car = 25 / 0.5
Average velocity of car = 50 km/h
If calcium carbonate (Cacos) decomposes. What would the product of the reaction be?
Answers
Answer:
CaO
Explanation:
Group 2 Carbonates decompose to form oxides of the Group 2 element and Carbon dioxide
Because electrons are orbiting the nucleus, the nucleus is stationary
true or false
Answers
Answer:
false, The nucleus of atoms still move around like crazy, it's just the electrons move more.
In the past mining companies were not made responsible for the clean-up of any of the mine sites. As a result, abandoned mines had a severe impact on the environment in Ontario. Which of these is not a result of these mining practices?
1) Chemical reactions producing sulphuric acid decrease soil and water PH in the area.
2) Acid leaching dissolves metals found in the soil thus allowing them to enter the water system.
3) Heavy metals which are left tailing ponds can dissolve and enter the water system.
4) Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Answers
Answer:
Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Explanation:
A smokestack, is a very tall channel commonly used in many instances to release gases produced by combustion processes directly into the air. These high towers are aimed at dispersing the gaseous pollutants over a wider area thereby minimizing their impact.
Old and inefficient smokestack do not contaminate the soil since they are very high towers that discharge gases directly into the atmosphere. Hence they are not part of the sources of soil contamination in abandoned mines.
cuantos gramos y moleculas de dioxido de carbono hay en 0.5 moles de dioxido de carbono
paso a paso
Answers
Answer:
metro= 22g
Explanation:
Cuando se quema 1 mol de metano –o sea, 16 g–, se desprenden 802
kJ/mol.
○ Cuando se quema 1 mol de octano –o sea, 114 g–, se desprenden 5500
kJ/mol.
Pareciera que el octano puede brindar más energía al quemarse, pero vamos a
hacer un análisis más cuidadoso. Comparemos la combustión de igual masa de
cada combustible.
● Calculen la cantidad de calor que se desprende cuando se quema un gramo
de cada combustible.
1 gr de metano aporta……………………………
1 gr de octano aporta………………………………
Answers
Answer:
1 gramo de metano aporta 50.125 kilojoules.
1 gramo de metano aporta 48.246 kilojoules.
Explanation:
La cantidad de energía liberada por la combustión de una unidad de masa del hidrocarburo ([tex]Q[/tex]), en kilojoules por mol, es igual a la cantidad de energía liberada por mol de compuesto ([tex]\bar {Q}[/tex]), en kilojoules por mol, dividido por su masa molar ([tex]M[/tex]), en gramos por mol:
[tex]Q = \frac{\bar Q}{M}[/tex] (1)
A continuación, analizamos cada caso:
Metano
[tex]Q = \frac{802\,\frac{kJ}{mol} }{16\,\frac{g}{mol} }[/tex]
[tex]Q = 50.125\,\frac{kJ}{g}[/tex]
1 gramo de metano aporta 50.125 kilojoules.
Octano
[tex]Q = \frac{5500\,\frac{kJ}{mol} }{114\,\frac{g}{mol} }[/tex]
[tex]Q = 48.246\,\frac{kJ}{mol}[/tex]
1 gramo de metano aporta 48.246 kilojoules.
What is the molarity of the solution formed by dissolving 80. G of NAOH(s) into water to give a total volume of 4.00 l
Answers
Answer:
0.5 M
Explanation:
From the question given above, the following data were obtained:
Mass of NaOH = 80 g
Volume of solution = 4 L
Molarity =?
Next, we shall determine the number of mole in 80 g of NaOH. This can be obtained as follow:
Mass of NaOH = 80 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass / molar mass
Mole of NaOH = 80 / 40
Mole of NaOH = 2 moles
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Mole of NaOH = 2 moles
Volume of solution = 4 L
Molarity =?
Molarity = mole / Volume
Molarity = 2/4
Molarity = 0.5 M
Therefore, the molarity of the solution is 0.5 M.
1.25 X 10^24 molecules of chlorine gas react with sodium to form how many grams of sodium
chloride?
2Na + Cl2
--> 2NaCl
Answers
Answer:
241.28 g NaCl(s)
Explanation:
Given 1.25 x 10²⁴ molecules of Cl₂ = 1.25 x 10²⁴molecules Cl₂(g)/6.023 x 10²³ molecules/mole = 2.08 mole Cl₂(g)
2Na(s) + Cl₂(g) => 2NaCl(s)
excess 2.08mole ? mole
∴moles NaCl(s) formed from 2.08 moles Cl₂(g) = 2(2.08 mole NaCl(s))
= 4.16 mole NaCl(g) = 4.16 mole NaCl(s) x 58 g NaCl(s)/mole NaCl(s) = 241.28 g NaCl(s)
C₂H₄O₂ + O₂ ➞ CO₂ + H₂O
Answers
Answer:
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
Explanation:
Start with the carbons
C2H4O2 + O2 ==> 2CO2 + H2O There are 2 on the left, so you need 2 on the right.
Next deal with the hydrogens. You have 4 on the left so you have to make 4 on the right
C2H4O2 + O2 ==> 2CO2 + 2H2O
The oxygens are the real devil in this question. Be careful how you handle them. There are 2 * 2 = 4 from the CO2 and 2*1 = 2 from the water. The total is 6
Now you can't just put a 3 in front of the O2. There are 2 in the given chemical. So you don't need 6. You need 6 -2 = 4. But the oxygen is O2. You have to divide the 4 by 2 to get 2
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
And that's your answer.
A heat lamp produces____
light.
Answers
Answer:
infrared light
Explanation:
if you have a pop quiz and you get nervous is that unconditioned response? if yes why? if not what kind of response is it
Answers
If you produce 35.7 grams of sodium chloride how many molecules of Chlorine gas were
needed?
2Na + Cl2 --> 2NaCl
(PLS HELP ASAP)
Answers
Explanation:
I did it in steps to help u to understand :)
Which is a constructive process? Rivers carrying sediment down stream, the rusting of a bridge, waves cutting back a beach front, volcanic eruption caused by plate tectonics
Answers
Answer:
volcanic eruption caused by plate tectonics.
Explanation:
Constructive process is one in which memories are influenced by some events. When a person tries to retrieve the memory he first click some event which is associated with that memory and then whole flash backs comes to his mind.
Which of the following equalities is not correct?
a. 1 cm^3 = 1 mL
b. 1000 mm = 1 m
c. 100 cg = 1 g
d. 10 kg = 1 g
Answers
Answer:
a. 1 cm^3 = 1 mL
explanation:
Stoichiometry - Chemistry
Answers
Answer:
C
Explanation:
in the option C when we rearrange it then it will he C3H6O2
Answer:
yes its C
Explanation:
correct me if iam wrong