Answer:
...
Explanation:
Calculate the average atomic mass of unknown element X. You determine that isotope 127X makes up 80%, isotope 126X makes up 17%, and isotope 128X makes up 3%.
A. 127.10 amu
B. 126.86 amu
C. 127.54 amu
D. 126.20 amu
Answer:
Option B. 126.68 amu
Explanation:
The following data were obtained from the question:
Isotope A (¹²⁷X):
Mass of A = 127
Abundance (A%) = 80%
Isotope B (¹²⁶X):
Mass of B = 126
Abundance (B%) = 17%
Isotope C (¹²⁸X):
Mass of C = 128
Abundance (C%) = 3%
Average atomic mass of element X =.?
Th4 average atomic mass of X can be obtained as follow:
Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(127 × 80)/100] + [(126 × 17)/100] + [(128 × 3)/100]
= 101.6 + 21.42 + 3.84
= 126.68 amu
Therefore, the average atomic mass of X is 126.68 amu
Plz help! :) :D I will mark you as BRAINLIEST for the best answer!!! ( I actually mean it)
Physical and Chemical Properties of Magnesium
Here is an EXAMPLE of how it has to be like. Instead of Mercury, you HAVE to do Magnesium
Physical Properties of Mercury: ”I’m a highly stable element, so you can count on me”
Chemical Properties of Mercury: ”I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”
Answer question number 3
Please choose the best description, or definition of Faunal Succession.
principle stating that specific groups of organisms lived and died within a specific
time frame due to the ice age
principle stating that specific groups of fawns lived in a specific region and are
found in the rocks shoing fawns onl live in specific areas.
principle stating that specific layers of the earth have contain fauna of different
types showing biodiversity.
rinciple stating that specific groups of organisms have followed, or succeeded.
one another in a definite sequence through Earth history
Answer:
Principle stating that specific groups of organisms have followed, or succeeded one another in a definite sequence through Earth history
Explanation:
Principle stating that specific groups of organisms have followed, or succeeded one another in a definite sequence through Earth history describe Faunal succession because it is a principle that indicate that fossil plants and animals succeed each other in a sequential manner even if they occur in different places. Successive strata and faunas are linked together to form composite section in the Earth's history.
Answer:
the last one
Explanation:
What will the coefficients be for the following balanced equation? (a) N2 + (b) H2 → (c) NH3
Answer:
his reaction is the synthesis of Ammonia using Nitrogen and Hydrogen gas.
N
+
H
→
N
H
3
We must remember that Nitrogen and Hydrogen are both diatomic molecules in their standard gas form. This adjusts the equation to
N
2
+
H
2
→
N
H
3
Now we need to adjust coefficients in order to balance the atoms on each side of the equation. Currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.
We can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.
N
2
+
3
H
2
→
2
N
H
3
This gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.
I hope this was helpful.
Explanation:
Answer:
1N2 + 3H2 →2NH3
Explanation:
Plato answer
A hypothetical element has two main isotopes with mass numbers of 59 and 62. If 73.00% of the isotopes have a mass number of 59 amu, what atomic weight should be listed on the periodic table for this element? Answer in units of amu.
since 73% of the isotope is given, take 100%-73% to get the remaining % of the isotopes which is going to be 27%.
hence,
atomic weight= (73×59) + (27×62)
=4307+1302
=5609 amu
Can an Atom be broken down into a smaller substance? Yes or No Explain.
Answer:
Yes
Explanation:
A atom is made out of 3 elements, protons which are positive charges, electrons which are negative charges that swirl around the atom, and a neutron with a neutral charge. The nucleus of the atom is basically the center of the atom.
The ___ has many functions; one is to regulate growth.
Growth hormon somatotropin
How many d electrons does I (atomic number
53) possess?
1. 10
2. 5
3. 8
4. 0
5. 20
6. 53
7. 16
Answer:
6. 53 is the answer. Hope this helps:)
The number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
What is an Atomic number?An atomic number may be defined as the number of protons in the nucleus of an atom that significantly represents the characteristic of a chemical element and determines its specific place in the modern periodic table.
According to the modern periodic table, an element that has an atomic number of 53 is known as Iodine. Its electronic configuration is [tex]1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^1^0, 4p^6, 5s^2, 4d^1^0, 5p^5[/tex]. Thus, according to this electronic configuration, the total number of d electrons are [tex]3d^1^0 and 4d^1^0[/tex].
Therefore, the number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
To learn more about Electronic configuration, refer to the link:
https://brainly.com/question/26084288
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4
The element bromine at room temperature is a liquid with a density of 3.12 g/nl.
Calculate the mass (wanted measurement) of 125 mL (given measurement) of bromine.
(use the given density as the conversion factor to calculate the wanted measurement).
Sign out
Calculate the number of moles of neon gas in 8.15 x 10^24 atoms of neon gas.
1.35 moles Ne
0.135 moles Ne
135 moles Ne
13.5 moles Ne
Answer:
13.5 moles of Ne
Explanation:
1 mole of any gas contains 6.02 x 10²³ atoms of gas
6.02 x 10²³ atoms of neon is equal to 1 mole of neon .
8.15 x 10²⁴ atoms of neon is equal to 1 x 8.15 x 10²⁴ / 6.02 x 10²³ moles
= 8.15 x 10²⁴ / 6.02 x 10²³ mole o neon
= 13.5 moles of Ne .
What physical property of the metal rods was being tested during step 4 of the procudure?
4. Measure and record how long it takes heat from the hot plate set on "high" to melt the wax ball.
A.
magnetism
B.
thermal conductivity
C.
electrical conductivity
D.
density
Answer:
B. thermal conductivity
Explanation:
They physical property being tested during the fourth step is the thermal conductivity of the materials.
Thermal conductivity is the ability of a body to transmit heat energy from one place to another.
Since we are measuring how long it takes for heat from the hot plate to reach the wax ball, this is a typical experiment for measuring thermal conductivity. Most metals are good conductors and heat energy moves fast in them.Non-metals are poor conductors with low thermal conductivity.
Which of the following is considered a sign of a chemical change?
How long will it take for 500.0g of radium decay to 2.0g
How many moles of gold, a U, are in 3.60×10^-5 G of gold?
Answer:
See Below.
Explanation:
This is a conversion problem:
Using the molar mass of Gold (given in a periodic table) which is 196.97g/mol
you have
[tex](3.60*10^-5 g) *\frac{1moles}{196.97g}[/tex]
you always arrange the equation in a way to cancel whatever you don't want (grams) and leave what you do want (moles). Here grams cancel (top and bottom), so you're left with:
[tex]\frac{(3.60*10^-5 g) *(1)}{196.97} = 1.83*10^-7[/tex] moles of Gold
An increase in which of the following would increase the boiling point of a
liquid?
Answer:
The boiling point increases with increased pressure up to the critical point, where the gas and liquid properties become identical.
Which types of reactions would result in the formation of precipitate?
Answer:
Double Displacement Reaction
Explanation:
A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.
What are two properties of most nonmetals
Answer: Summary of Common Properties
High ionization energies.High electronegativities.Poor thermal conductors.Poor electrical conductors.Brittle solids—not malleable or ductile.Little or no metallic luster.Gain electrons easily.Dull, not metallic-shiny, although they may be colorful.Explanation:
May I please have brainiest?
Answer:
The two properties of most non metals are high ionization energy and poor electrical conductivity. The correct option among all the options that are given in the question is option "1". In general it is known that nonmetals are very poor conductors of heat and electricity. The nonmetals that are solid are normally very brittle and has very little or no metallic luster at all. Nonmetals are highly reactive and show variety of chemical properties. It can also be pointed out that the nonmetals gain electrons very easily.
brainliest pleaseee :)
What type of heat transfer happens in the Inner Core?
Answer: Conduction
Explanation:
what is potiential and kinetic engergy? pls someone answer my question
Answer:
Potential Energy is stored energy or energy of position (gravitational). The object isn't moving. For example, a ball being held is potential energy because the object isn't moving but it has the potential of turning into kinetic energy.
Kinetic Energy is the energy of motion. For example, running. You are moving, and there is clear action and activity
Energy stored in an object due to its position is Potiential energy . Energy that is moving object has due to its motion is Kinetic energy .
4. Advection fog forms when warm moist air comes in from the Pacific Ocean and
blows over the cold California current.
A.True
B.False
Answer:
A, True
Explanation:
Explain why the mass number of oxygen is 16
Answer:
Oxygen has an atomic number of 8 , and the mass number of an atom is the sum of its atomic number plus its neutron number. We got the mass as 16 units, and so it'll have 16−8=8 neutrons.
Explanation:
PLZ HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Reactivity
Explanation:
Luster. Ductile, and Malleabillity are all physical.
Select the molecular shape of each molecule based on the formula or Lewis structure.
Answer:
1. linear (A)
2. trigonal-planar (C)
3. tetrahedral (B)
4. linear (A)
Explanation:
Just did it on Edge 2020
The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
The Valence Shell Electron Pair repulsion theory gives us a basis for predicting the shape of molecules. The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
In the image shown, We can see that in HCN , carbon is the central atom and is surrounded by two atoms and no lone pairs. Since there are two electron domains around the central atom, the molecule is linear.
In the second structure, BH3 has boron as its central atom. Three electron domains surround the central atom hence the molecule is trigonal planar.
Learn more: https://brainly.com/question/25249351
?
The group number tells the number of
Elements in the column
Number of valence electrons
O Number of energy levels
O Number of protons in the elements
Answer:
number of valence electrons
Explanation:
elements in the same group has same number of valence electrons
Assume that the pendulum clock shown in the photograph is a closed
system
Which statement describes evidence that the pendulum's energy is conserved
even as it eventually stops moving?
A. Energy must be added to the pendulum to keep it from slowing
down
B. Some of the clock's matter is transformed into new energy
C. The amount of each type of energy in the system can be
measured
D. All its mechanical energy is transformed into other forms of
energy
Answer:
Explanation:
d
Answer:
D. All it’s mechanical energy is transformed into other forms of energy.
Explanation:
I got it right
Which of the following elements has the largest electronegativity? A) Bismuth B) Nitrogen C) Potassium D) Arsenic
How many moles are in 5.25 X 10 25
atoms of Au?
Answer:
The answer is 87.21 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{5.25 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 87.2093023...[/tex]
We have the final answer as
87.21 molesHope this helps you
Joe bought a roll of gray duct tape containing 5400 inches. If there are 5280 feet in a mile, how
many miles long is Joe's roll of duct tape?
Answer:
STANDARD: 0.085 mi, 450 ft, or 150 yds
METRIC: 0.137 km, 137.16 m, or 13716 cm
Explanation:
A sample of N2H4 has a mass of 25g. Identify the numerical quantity that is needed to convert the number of grams of N2H4 to the number of moles of N2H4. (You do not need to do the actual calculation.)
Answer:
Molecular Mass
Explanation:
It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.
(14g N * 2) + (1g H *4) = 32g / mol of N2H4
To get # of moles, divide the sample mass by the molecular mass
25g / 32g = 0.78125 moles