Answer:
0 C
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
A runner completes a 400m race in 43.9s. What is his average speed?
Answer:
average speed around 9.1 meters/second
Explanation:
400 divided by 43.9
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.?
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
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
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 .
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”
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 :)
Determine the mass of 31.4 moles of Sodium.
Answer:
721.9 grams
I hope this helps!
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 .
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
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:
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.
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
All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down an object, what is most likely true about the surface the object is moving on? The surface is dry. The surface is rough. The surface is uneven. The surface is smooth.
The question is incomplete, the complete question is;
All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down and object, what is MOST LIKELY true about the surface the object is moving on? (A) The surface is dry (B) The surface is rough (C) The surface is uneven (D) The surface is smooth
Answer:
(D) The surface is smooth
Explanation:
Friction exists because of relative motion between two surfaces in contact with each other. However the magnitude of friction depends on how rough or smooth the surface is.
For smooth surfaces, there is little or no resistance to motion as objects move over the surface. Hence objects take a longer time to slow down on a smooth surface due to very little friction.
On a rough surface, objects tend to slow down relatively quickly. Hence, less resistance to motion on a smooth surface makes an object to take a longer time to slow down on a smooth surface than on a rough surface.
Answer: D
Explanation: Because if the surface is smooth it causes it to be more even for it to be able to cause Friction
if you find this helpful, Your welcome, if not, sorry.
A piece of gold has a mass of 21.7 kg and a volume of 5.78 cm3 . What is the density of gold? (Convert kgg)
Answer:
The answer is 3754.33 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 21.7 kg = 21700 g
volume = 5.78 cm³
We have
[tex]density = \frac{21700}{5.78} \\ = 3754.3252...[/tex]
We have the final answer as
3754.33 g/cm³Hope this helps you
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
#SPJ2
Answer question number 3
What is the volume of a weather balloon that has 39 grams of helium with a density 0.017 g/mL?
Answer:
The answer is 235.29 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question.
density = 0.017 g/mL
mass = 4 g
We have
[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]
We have the final answer as
235.29 mLHope this helps you
Which of the following atoms has the greatest ionization energy?
a.)W
b.)C
C.)d
P.)d
Answer:
helium
Explanation:
because there are no electrons screening it from the nucleus
Which of the following happens to the particles when the temperature of liquid water drops?
Explanation:
when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle
1. The human eye can detect wavelengths of light as short as 0.000037 cm. What is this
wavelength in nanometers?
Answer:
0.000037 cm is 370 nanometers
Explanation:
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:
Which of the following is considered a sign of a chemical change?
What type of heat transfer happens in the Inner Core?
Answer: Conduction
Explanation:
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.
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
How long will it take for 500.0g of radium decay to 2.0g
Which of the following elements has the largest electronegativity? A) Bismuth B) Nitrogen C) Potassium D) Arsenic
Why can two water molecules stick to each other?