Which describes an element?

A.They cannot be broken down any further.
B.They can combine with other elements to form atoms.
C.They were all discovered at the same time.
D.They were created in the Earth’s core.

Answer:

Explanation:

Speed and velocity I think

Answer:

a gallon of water weighs more than a gallon of butane

Answer: The iron equilibrium is the more positive, and so will go in the forward direction. The tin equilibrium is less positive (more negative), and will be driven backwards. So the tin(II) ions will reduce iron(III) ions to iron(II) ions. In the process, of course, the tin(II) ions will be oxidised to tin(IV) ions.

Explanation:

Answer:

You have to remember this memory aid, diagonals and all.

You have to keep a tight tally of the electrons you’ve used so far so you don’t go over the number of electrons in the element you’re working on.

You have to remember how many electrons fit into each subshell (s, p, d, f).

It takes a lot of time, especially when the element has more than 20 electrons.

Explanation:

Answer:

chlorine is a non metal.

sodium is a alkali metal.

helium is a noble gas.

nickel is a transition metal

Answer:

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A reaction is said to have reached equilibrium when the reaction rate is equal in both directions (c).

Like, take the example of copper in copper sulphate solution. When you add Cu to CuSO4 soln., there won't be any change occurring as the reaction rate is equal (Cu is added to CuSO4 soln., there won't be any change as displacement reaction won't take place due to Cu being the same metal as in CuS04 soln...their reaction is the same).

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RainbowSalt2222 ☔

This question involves the concepts of de Broglie's wavelength and momentum.

The velocity of the electron must be "1754.27 m/s".

de Broglie's wavelength is a wavelength associated with a moving matter particle. It is connected to the momentum of the particle by the following formula:

[tex]P =\frac{h}{\lambda}\\\\mv=\frac{h}{\lambda}\\\\v=\frac{h}{m\lambda}\\\\[/tex]

where,

v = velocity of electron = ?

h = Plamk's Constant = 6.625 x 10⁻³⁴ J.s

m = mass of electron = 9.1 x 10⁻³¹ kg

λ = de Broglie's wavelength = 415 nm = 4.15 x 10⁻⁷ m

Therefrore,

[tex]v=\frac{6.625\ x\ 10^{-34}\ J.s}{(9.1\ x\ 10^{-31}\ kg)(4.15\ x\ 10^{-7}\ m)}[/tex]

v = 1754.27 m/s

Learn more about de Broglie's wavelength here:

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Answer:

b

Explanation:

north is up south is bottom

Answer:

C. South pole on the left end and north pole on the right end

Explanation:

From the figure, we can conclude that the poles of the magnet are on either sides of the magnet

Therefore, options 1 and 2 are excluded

It is a convention that the magnetic field lines move out of the north pole of a magnet and into the south pole of the magnet

From the figure, we can see that the magnetic field lines are moving out from the right end and into the left end

This means that the north pole is at the right end and that the south pole is at the left one

Answer:

it can be done using the method of lithium paper

Answer:

3 valence electrons

Explanation:

Aluminum has three valence electrons. Valence electrons are found in the outermost shell of an element and are responsible for its valence.

Frequency – The frequency of a wave is the number of waves that pass a given point in a certain amount of time. Frequency is measured in units called hertz (Hz), and is defined as the number of waves per second. A wave that occurs every second has a frequency of 1 wave per second (1/s) or 1 Hz.

Answer:

The high melting point is also consistent with its description as an ionic solid. In the crystal, each S2− ion is surrounded by an octahedron of six Ca2+ ions, and complementarity, each Ca2+ ion surrounded by six S2− ions.

Explanation:

You can use the periodic table to predict whether an atom will form an anion or a cation, and you can often predict the charge of the resulting ion. Atoms of many main-group metals lose enough electrons to leave them with the same number of electrons as an atom of the preceding noble gas. To illustrate, an atom of an alkali metal (group 1) loses one electron and forms a cation with a 1+ charge; an alkaline earth metal (group 2) loses two electrons and forms a cation with a 2+ charge, and so on. For example, a neutral calcium atom, with 20 protons and 20 electrons, readily loses two electrons. This results in a cation with 20 protons, 18 electrons, and a 2+ charge. It has the same number of electrons as atoms of the preceding noble gas, argon, and is symbolized Ca2+. The name of a metal ion is the same as the name of the metal atom from which it forms, so Ca2+ is called a calcium ion.

When atoms of nonmetal elements form ions, they generally gain enough electrons to give them the same number of electrons as an atom of the next noble gas in the periodic table. Atoms of group 17 gain one electron and form anions with a 1− charge; atoms of group 16 gain two electrons and form ions with a 2− charge, and so on. For example, the neutral bromine atom, with 35 protons and 35 electrons, can gain one electron to provide it with 36 electrons. This results in an anion with 35 protons, 36 electrons, and a 1− charge. It has the same number of electrons as atoms of the next noble gas, krypton, and is symbolized Br−. (A discussion of the theory supporting the favored status of noble gas electron numbers reflected in these predictive rules for ion formation is provided in a later chapter of this text.)

Explanation:

Here you go, my teacher hasnt graded it yet.

Answer:

Sodium and Potassium only

Answer: If two positive charges interact, their forces are directed against each other. The two charges repel each other.

Explanation: The same occurs with two negative charges, because their respective forces also act in opposite directions.) The electric field and resulting forces produced by two electrical charges of the same polarity.

Good luck luv.

what describes “Al” is chemical Symbols.

It is not atomic mass because atomic mass is the quantity of matter contained in an atom of an element.

It is not atomic number because it's the number of proton in an atom of an

element.  

The above description "Al" is a chemical symbols.

Chemical symbols are used to represents elements in the periodic table.

The element represented is aluminium.

learn more about chemical symbols: https://brainly.com/question/18919028?referrer=searchResults

Answer:

Explanation:

Answer:

A

Explanation:

The substance is a gas because the particles far randomly arranged and far apart from each other. This happens because when a substance is a gas, particles have weak attraction to each but a lot more kinetic energy which means the they move around all the time spreading out to fill the container. If it was a solid, then all the particles would be very close together and have a fixed position and if it was a liquid then the particles would be fairly close and moving around each other but as we can see in the diagram, all the particles are far apart confirming that it is a gas.

Answer:

the answer is A beacause the other person is right :)

Explanation:

please give them brainliest

Answer:

Burning fossil fuels emits a number of air pollutants that are harmful to both the environment and public health. Sulfur dioxide (SO2) emissions ...

Por definición de enlace iónico, covalente y regla del octeto, la relación existente entre la teoría del octeto de Lewis con los enlaces iónicos y  covalentes es que dichos enlaces se producen con el objetivo de completar la última capa de electrones y adquirir estabilidad.

Por un lado, se produce un enlace iónico entre átomos metálicos y no metálicos, donde los electrones se transfieren completamente de un átomo a otro. Durante este proceso, un átomo pierde electrones y otro los gana, formando iones. Por lo general, el metal cede sus electrones formando un catión al elemento no metálico, que forma un anión.

Por otro lado, el enlace covalente es el enlace químico entre átomos donde los electrones se comparten, formando una molécula. Se establecen enlaces covalentes entre elementos no metálicos. El par de electrones compartidos es común a los dos átomos y los mantiene unidos.

En ambos casos se cumple con la regla del octeto, que establece que los átomos de los elementos se enlazan unos a otros en el intento de completar su capa de valencia con ocho electrones. Es decir que los átomos van a tender a ceder o compartir electrones para completar ocho electrones en la capa de valencia mediante un enlace iónico, covalente o metálico.

En otras palabras, el objetivo es tener la configuración electrónica del gas noble más cercano, teniendo así la última capa de electrones completa y adquiriendo estabilidad.

En resumen, la relación existente entre la teoría del octeto de Lewis con los enlaces iónicos y  covalentes es que dichos enlaces se producen con el objetivo de completar la última capa de electrones y adquirir estabilidad.

Aprende más:

Answer:

Explanation:

Answer:

Electrochemistry

Explanation:

Answer:

Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. That's because a great deal of energy is needed to overcome the force of repulsion between the positively charged nuclei.

Explanation:

hope it helps

Answer:

Scientists use models to study atoms because atoms are extremely small and can't even be seen. If atoms can't be seen, it's easier to study and.

Explanation:

hope it helps you

Answer:

You did very well and its correct.

Explanation:

Great Job!

Answer:

[tex]50.0 \div 59.0 = 10[/tex]

right