Originally, the periodic table was ordered by atomic weight, but there were some problems with this order for some particular cases.
In 1913 Moseley proposes to use the atomic number (number of protons of the atom) to order the elements in the periodic table. There are some motives to do this, each element has a different number of protons, and if you add one proton to the nucleus, you get the next element in the periodic table.
This also relates to the x-ray diffraction of the elements (as the number of protons increase, also do the numbers of electrons, thus the energy of the x-rays also increases). At the moment this was the best way to order the periodic table, but in recent years some problems were found, but at the moment, there does not exist a "better" periodic order.
Concluding, the correct option is "atomic number".
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Answer:
1. Which statement about metals and nonmetals is correct?
*Metals can be hammered into thin sheets, and nonmetals are brittle.*
2. Based on properties of elements in the periodic table, which element is the best conductor of thermal energy?
*vanadium (V)*
3. Which element has four valence electrons?
*silicon (Si)*
4. Which statement best explains why hydrogen’s atomic number is equal to its mass?
*Hydrogen does not have any neutrons.*
5. Which statement correctly compares the valence electrons for atoms of francium (Fr) and barium (Ba)?
*Francium has fewer valence electrons, but they are in a higher energy level.*
6. Gallium has an atomic number of 31 and a mass number of 70. Which table shows the number of protons, neutrons, and electrons in a gallium ion with a +3 charge?
*protons 31, neutrons 39, electrons 28*
7. Which is true about about stable isotopes?
*A stable nucleus has a similar number of protons and neutrons.*
8. On which atomic property proposed by Henry Moseley is the current periodic table of the elements based?
*atomic number*
9. Which incorrect aspect of Rutherford’s model was fixed by Bohr’s model?
*Electrons move freely in curved paths around the nucleus.*
10. You plan to pass alpha particles through a field that contains a consistent type of particle. Which configuration will result in the largest deflection of alpha particles?
*low-energy alpha particles passing through a field of high mass-number-particles*
11. Where on the periodic table do you find elements that have full valence electron shells?
*on the right side of the periodic table*
12. Which element would have a full outer shell of electrons if it gained three electrons?
*nitrogen*
13. Which group of elements has the most similar chemical properties?
*fluorine, chlorine, and iodine*
14. Group 2 elements have two valence electrons. Which kind of bond will they most likely form, and why?
*An ionic bond is likely because they will want to give away two valence electrons in order to become stable.*
15. An element has six valence electrons. Which ionic charge will its ion carry?
*2–*
16 and 17 are writing.
Explanation:
These are the correct answers for The Periodic Table Unit Test.
Explain one rule of Ultimate Frisbee.
Explanation:
The object of Ultimate Frisbee is to gain points by scoring goals. The disc may only be passed, and a goal is scored when a player successfully passes the disc to a teammate in the end zone which that team is attacking. The team with the most points at the end of the game is declared the winner.
Mass is measured in
a) Litters
b) Centimeter
c) Newton
d) Kilogram
Answer:
d) Kilogram.
Hope it helps youMass is measured in
a) Litters
b) Centimeter
c) Newton
d) Kilogram
Calculate the electrical energy transferred by a 60W electric bulb that is turned on for 20s and 5minutes.
Answer:
approximately 0.00504 kWh
Explanation:
This electrical energy and is measured in kWh.
For 5 minutes and 20 seconds of use, it is 0.06 W x 0.084 h = 0.00504 kWh.
Note: 60W = 0.06kW; 5min 20sec = 0.083(8) ≈ 0.084 hour
how many seconds are there in 1 day . solve along with steps
One minute has 60 seconds, One hour has 60 minutes and one day has 24 hours. Thus, 80 x 60 x 24 = 86,400 sec
if my answer helps you than mark me as brainliest
Answer:
[tex]thank \: you[/tex]
Please help me, I really need someone
Answer:
In plotting position versus time it can be seen that the green line represents a fixed position at the various times given - the other lines represent changing position with time
The (horizontal) green line describes an object that's not moving.
Whatever TIME you pick to look at the green line, its POSITION is always the same. This is a pretty good description of "not moving".
The other three lines all have different positions at different times, so they all describe motion.
It takes Serina 0.25 hours to drive to school. Her route is 16 km long. What is Serina’s average speed on her drive to school?
Answer:
[tex]velocity = \frac{speed}{time} \\ = \frac{16}{.25} \\ \frac{16}{ \frac{1}{4} }(.25 = \frac{1}{4}) \\ 16 \times 4 = 64 km/hour\\ thank \: you[/tex]
If a body is dropped from the same height once in the equator and then in polar region in which place will it fall faster? why
Explanation:
equator.
because the "belly" of the Earth around the equator makes the Earth there thicker than from pole to pole.
the reason is the spinning of our planet. as the spinning speed is the fastest at the thickest part of a ball (at the equator), that ball has the tendency due to the centrifugal force to extend even further there, and the extra material for that is being pulled in from the poles.
therefore, the diameter through the Earth from equator to equator is larger than the diameter from pole to pole.
and that means that there is more mass from equator to equator than from pole to pole.
and that means that gravity is stronger at the equator.
therefore, a body will fall faster at the equator than on a pole.
What does v or vf stand for? What SI units are used to measure it?
Answer:
Ventricular Fibrillation
Explanation:
it is measured bpm ( beats per minute ) of the cardiac muscles of the heart in a poor / disorderly working condition.
Answer:
velocity and final velocity (m/s)
Explanation:
Write an ecosystem report on rain.
Answer:
Explanation:
kopkpo
???????.............please help:)
Answer:
It is:
0.00477
0.00000301
what is the atomic mass of oxygen?
Answer:
[tex]atomic \: mass \: of \: oxygen = 15.99aproximtly = 16 \\ thank \: you[/tex]
Answer:
The atomic mass of oxygen is 15.999 u.
Someone please help me!! See PDF to help
Answer:
They are invisible!
Explanation:
Explanation:
They are invisible is the answer.
A mother finds her daughter’s mug of hot cocoa on a table an hour after she had been drinking it. As the mother pours out the cocoa, she sees brown solids in the bottom of the mug. How can this be explained?(1 point)
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility went up.
All dissolved substances will come out of solution over time. If the mother waits long enough, then all of the powder will appear at the bottom of the mug.
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility went down.
This would only happen if too much cocoa powder was added in the first place, because the solubility should not change.
Answer:
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility went down.
Answer:
C
Explanation:
Math is used in the sciences because (1 point)
A numbers are the best way to understand scientific ideas.
B it is a universal means of communicating scientific information.
C scientific data is quantitative.
D scientific data requires significant figures.
Which option is the appropriate scientific unit for distance?
A) Foot
B) meter
C) mile
D) yard
Which tools do investigations in Earth and space science use?
A) computer and field
B) internet and laboratory
C) computer, laboratory and field
D) computer, internet, laboratory, and field
Answer:
1. it is universal means of communicating scientific information
2. meter
3. computer, internet, laboratory, and field
A tall tree has more chance to break during storm why
Answer:
yes
Explanation:
because the strong winds and the weight and there are more things to break
Explanation:
A tall tree may have more resistance to the wind since it has more mass ( branches, leaves). That means the wind has more mass to push against. Winds may also be stronger at a higher level. Tall trees have been growing longer and have more chances to have been compromised by insects, animals, fungi and so on. They also have less flexibility since they need to be more rigid to hold up the mass of branches they have.
A still object has a mass of 25kg, what would be the Weight? What would be the Normal Force?
[tex]\\ \rm\longmapsto Force=Mass(Acceleration)[/tex]
[tex]\\ \rm\longmapsto Force=25(10)[/tex]
[tex]\\ \rm\longmapsto Force=250N[/tex]
can you convert liters to kilometers explain ur answer plsss
Answer:
Yes we can.
Explanation:
1 Litre= 0.001km
1000 Litre= 1km
1. Alice decides to measure the density of the banana.
a)What equipment will she need to measure it?
b)Explain how she could use that equipment to measure the density.
Answer:
A) Measuring cup with water and a scale
Explanation:
Fill the measuring cup with water to a certain point, and record the current height of the water. After placing the banana fully into the water, record the new height of the water. Subtract the old height from the new height. Now you have the banana's volume.
Then, place the banana on a scale to get it's mass.
Perform [tex]\rho ={\frac {m}{V}}[/tex], where p = density, m = mass, v = volume.
Note: 1 milliliter = 1 centimeter^3
pls help question are in the picture
Fluorescent lamp of 25W gives more light than the filament lamp of 50W. Why?
Answer:
Fluorescent lamp releases more light energy.
Explanation:
This is so because the fluorescent lamp releases more light energy and less heat energy than that of a filament lamp with the same rating.
Fluorescent lamp releases more light energy than that of filament lamp and also less heat energy than that of a filament lamp.
What is Power of fluorescent lamp and filament lamp?The filament and the fluorescent lamps are two different types of most commonly used light lamps. The filament lamps are the lamps which work on the phenomenon of incandescent whereas a high resistance filament is heated up in the lamp until it radiates visible light energy. Whereas, a fluorescent lamp is the lamp which works by ionizing a gas that emits photons or energy particles.
The fluorescent lamp releases more light energy and less heat energy than that of a typical filament lamp with the less power of 25W than 50W.
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A car drives around the block 400m. What is the distance ?
0 40000m
4 m
400m
O 0.4 m
The distance traveled by the car will be equal to 400 m.
The given parameter
distance round the block, d = 400 m
To find:
the distance traveled by a car round the blockTo travel round the block means that the car will complete a distance equal to the distance round the block.
distance round the block = distance traveled by the car = 400 mThus, the distance traveled by the car will be equal to 400 m, since this is equivalent to the distance round the block.
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Between which types of elements do ionic bonds occur, and how do electrons act within the bond?(1 point)
nonmetals and nonmetals, electrons shared
metals and nonmetals, electrons transferred
metals and metals, electrons freely moving
nonmetals and metals, electrons shared
Answer:
Im pretty sure that its, the metals and nonmetals, electrons transferred.
Between metals and nonmetals, types of elements do ionic bonds occur, and electrons transferred within the bond,therefore the correct answer is option B.
What is an ionic bond?When two similar or dissimilar atoms form bonds with each other by transferring their valence electron the bond is known as the ionic bond.
The ionic bond is the result of the transfer of the electrons
Ionic bonds are formed between the pair of one electronegative atom and an electropositive atom.
Ionic, covalent, and hydrogen bonds are the three basic types of chemical bonds that are used to generate these chemical compounds from their component atoms.
Ionic bonds are created when electrons are transferred between two bond-forming pairs that can be distinguished by their electronegativity.
Thus, Between metals and nonmetals, types of elements do ionic bonds occur, and electrons are transferred within the bond, therefore the correct answer is option B
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show with the help of an experiment that the acceleration of a freely falling body doesn't depend on the mass of that body. pls answer this question:)
Answer:
Experiment
Materials needed
Stop watch, a small stone, a big stone, a balance.
Procedure
Measure the mass of the two stones.
Hold the two stones about 5m above the ground level.
Drop the stones simultaneously.
Record the time taken for the stones to strike the ground.
Repeat the procedure with different masses of objects at the same height.
Observation, it will be observed that, all the objects dropped from the same height strike the ground at the same time interval.
Conclusion; a falling object doesn't depend on mass
Explanation:
½mv²=mgh
g=½(V²/h)
When an object is held at a height, it posses gravitational potential energy which is mgh, where m= mass, h=height, g=acceleration due gravity
When the object is dropped, the potential energy will be converted to kinetic energy which is ½mv², where V=velocity at which the object moves.
V=∆h/t, ∆h is change in height with respect to time.
½mv²=mgh
Mass cancel out,
g=v²/2h
This implies that g does not depend or is not affected by mass. Hence heavy object and light object will reach the ground at the same time when dropped from the same height. When air resistance is negligible.
How are the oscillating magnetic and electric fields of an electromagnetic wave positioned relative to each other?
Answer:
Electromagnetic waves consist of both electric and magnetic field waves. These waves oscillate in perpendicular planes with respect to each other, and are in phase. The creation of all electromagnetic waves begins with an oscillating charged particle, which creates oscillating electric and magnetic fields.
Explanation:
When a wave moves from one medium into another at an angle other than 90o the wave will change direction and continue to follow a new straight-line path. This is known as and is responsible for the of white light into its component colors when it passes through a prism.
Answer:
Mono-chromatic, Poly-chromatic. When a wave moves from one medium into another at an angle other than 90 degrees the wave will change direction and continue to follow a new straight-line path
Thank you
what is the acceleration of a car that goes from 4m/s to 8m/s in 2s use the guess method
Answer:
12m/3s is the answer I hope its right...A stone of mass 600g is thrown vertically upwards. calculate the value of the gravitational force on the stone at its highest point. take g = 10N/kg
Answer:
6N
Explanation:
F = m × g
= 0.6 × 10
= 6N
to find the force you first have to convert the mass to kg by dividing 600 by 1000 giving you 0.6
then you can multiply the mass times the gravity giving you a gravitational force of 6N
Two representative elements are in the same period of the periodic table. Which statement correctly describes the atoms of the two elements?(1 point)
They have the same number of valence electrons.
They have the same number of valence electrons.
They have valence electrons in different energy levels.
They have valence electrons in different energy levels.
They have valence electrons in the same energy level.
They have valence electrons in the same energy level.
They have the same number of electrons.Helium is in group 18 of the periodic table. How is helium different from the other elements in this group?(1 point)Helium atoms have valence electrons in the first energy level, while atoms of the other elements in the group have valence electrons in the second energy level.
Helium atoms have valence electrons in the first energy level, while atoms of the other elements in the group have valence electrons in the second energy level.
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
Helium atoms have a full outer energy level, while atoms of the other elements in the group do not have a full outer energy level.
Helium atoms have a full outer energy level, while atoms of the other elements in the group do not have a full outer energy level.
Helium atoms have 2 electrons, while atoms of the other elements in the group all have 18 electrons.
Use the periodic table to answer the question.
Which element has atoms with valence electrons in a higher energy level than those of calcium (Ca)?
lithium (Li)
lithium (Li)
cesium (Cs)
bromine (Br)
oxygen (O)
Use the periodic table to answer the question.
Which statement best describes the arrangement of electrons in an atom of fluorine (F)?
There are seven electrons in the first energy level and two electrons in the second energy level.
There are seven electrons in the first energy level and two electrons in the second energy level.
There are five electrons in the first energy level and two electrons in the second energy level.
There are five electrons in the first energy level and two electrons in the second energy level.
There are two electrons in the first energy level and seven electrons in the second energy level.
There are two electrons in the first energy level and seven electrons in the second energy level.
There are two electrons in the first energy level and five electrons in the second energy level.
1) They have valence electrons in the same energy level.
2) Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
3) cesium (Cs)
4) There are two electrons in the first energy level and seven electrons in the second energy level.
In the periodic table, elements are arranged in order of increasing atomic number into groups and periods.
In the periodic table, we have an arrangement of atoms based on their respective groups and periods.
If I pick two representative elements in the same period, their number of valence electrons will differ by 1 but they will all be accommodated in the same energy level.
Helium is the first member of group 18. Unlike the other members of the group, its first shell is also its valence shell. It has two and not eight valence electrons like other members of the group.
The electronic configuration of Ca is [Ar] 4s², that of Li is [He] 2s1, that of Cs is [Xe] 6s1, that of Br is [Ar] 4s² 3d¹⁰ 4p⁵ and that of oxygen is [He] 2s² 2p⁴.
We can see that only Cs has valence electrons in higher energy orbitals than those of Ca.
Lastly, Fluorine is in group 17. There are nine electrons in this atoms. They arranged in such a way that there are two electrons in the first shell and seven electrons in the second shell.
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-. JC=BFF© cough medicine is marketing its' new medicine called "Devil Red". They
want to know why religious customers seem to avoid their product.
Religious customers seem to avoid their products because;
they have a negative view and understanding of the name "Devil."When selling a product to potential customers, the brand name of that product could affect sales negatively or positively.
Religious people do not view the devil in a positive manner because they believe that he is responsible for the suffering in the world.
The already existing bias they have in their minds about that name will make them reject any product bearing the name. They might even reason that this medicine will worsen their sickness. For this reason, the medicine called "Devil Red" will have a poor reception by religious people.
Summarily, religious people avid the medicine called Devil Red because they have a negative view of the devil.
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While swimming a person pushes water backward, why?
Answer:
THIS DUE TO THE THIRD LAW OF MOTION.
AS WE PUSH WATER BACKWARD THE WATER WITH SAME FORCE BUT EQUAL DIRECTION PUSHES US SO WE GO IN FORWARD DIRECTION.
Explanation:
While swimming a person pushes water backward because the pushing action create reaction due to which we move forward while swimming.