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3 years ago

A chemical reaction [can/cannot] change an element into another element.

1 answer:

7 0

Depending on the context of your question: a chemical reaction can not! but Alpha decay is a kind of radioactive decay in which an alpha particle is emitted from an atom. An alpha particle consists of two protons and two neutrons. Therefore, when an atom of an element undergoes alpha decay, it loses two protons, which changes the atom from one element to another. This is because each different element is identified by the number of protons in its atomic nuclei.

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People who r good at physics pls help...

malfutka [58]

Answer:

Speed and velocity both measure an object’s rate of motion. However, speed is a scalar quantity, which means that it can be described with a numerical value. Velocity is a vector quantity, which depends on direction as well as magnitude. Read these definition for more information:

speed - the rate of distance traveled by a moving object over time

velocity - the rate of displacement of a moving object over time

Basically, an object’s speed tells you how fast it’s going. Its velocity tells you how fast it’s going in a certain direction. You use speed measurements in your daily life, but physicists depend on velocity measurements more frequently in their work.

Explanation:

5 0

3 years ago

The temperature of a gas is _____.

kykrilka [37]

Directly proportional to pressure

8 0

3 years ago

Read 2 more answers

A force does work on an object if a component of the force is

IrinaK [193]

Answer:

A force does work on an object if a component of the force is parallel to the displacement of the object.

Explanation:

Work, a measurement of energy is said to be done when a force applied to an object results in the movement of that object to a certain distance and direction. Force is the act of push or pulls occurs on an object as a result of the interaction between that object with another one and displacement is the distance and direction covered by that object as a result of the force applied on it.

The work done (W) by a constant force (F) is equal to the product of the force in the direction of displacement of the object and the distance (d) moved by the object i.e., W = F * d.

The angle between the displacement and the force is θ, then the work done, W = Fd cos θ ........ (1)

Positive work - Force acts in the same direction with respect to the displacement of the object. Here, θ is zero, so cos θ i.e., cos 0 is 1. Therefore, from the equation (1), W = Fd (i.e., work done by the force is positive).

Negative work - Force acts in the opposite direction with respect to the displacement of the object. Here, θ is 180°, so cos θ i.e., cos 180° is -1. Therefore, from the equation (1), W = -Fd (i.e., work done by the force is negative).

If a force is applied to an object and it does not move, then the work done is zero i.e., W = F * 0 = 0. Also, if the force and displacement are at right angle to each other, then θ is 90°. Therefore, from the equation (1), W = 0 since cos 90° is zero.

7 0

4 years ago

What initially unknown quantity, together with the wavelength, is sufficient to calculate the stopping potential for 400 nmnm li

kondaur [170]

Answer:

The initially known quantity, together with the wavelength, that is sufficient to calculate the stopping potential for electrons from the surface of a metal is called the WORK FUNCTION.

Explanation:

The stopping potential is defined as the potential that is required to stop electrons from being ejected from the surface of a metal when light with energy greater than the metal's work function/work potential is incident on the metal.

Given that light is known to be made up of photons, which carry energy in packets according to the frequencies of the light.

The photoelectric phenomenon explains that when light of a certain frequency that corresponds to an energy level that is higher than a metal's work function is incident on a metal, it will lead to electrons being ejected from the surface of the metal. The energy of the ejected electrons is then proportional to the difference between the energy level of the photons and the metal's work function.

Basically, it is the excess energy after overcoming the work function that rejects the electrons.

So, to prevent this excess energy from ejecting electrons from a metal's surface, an energy thay matches this excess must be in place to stop electrons from coming out. This energy/potential required to stop the ejection of electrons, is called the stopping potential.

The stopping potential is given as

eV₀ = hf - ϕ

The stopping potential (eV₀) them depends on the hf and the ϕ.

hf is the energy of the photons, where h is Planck's constant and f is the photons' frequency which is further given as

f = (c/λ)

c = speed of light (speed of the photons)

λ = wavelength of the photons.

The other quantity, ϕ, is the metal's work function; the amount of energy needed to be overcome by the photons before ejection of electrons is possible. It is the minimum energy that the light photoms must possess to even stand a chance of being able to eject electrons from a metal's surface.

So, the stopping potential is the difference between the energy of the photons (obtained using the photons' frequency, wavelength and/or speed) and the metal's work function.

Hope this Helps!!!!

3 0

4 years ago

Two identical metal spheres a and b are connected by a plastic rod. both are initially neutral. 1.0×1012 electrons are added to

Ann [662]

The plastic rod is made of insulator (plastic), so it does not allow charges moving from one sphere to another. This means that all the electrons given to sphere A will remain on sphere A.

The number of electrons initially given to sphere A is $N=1.0 \cdot 10^{12}$ , and since the charge of 1 electron is $e=-1.6 \cdot 10^{-19} C$ , the net charge left on sphere A after the removal of the rod will be
$Q=N e = 1.0 \cdot 10^{12}(-1.6 \cdot 10^{-19} C)=-1.6.0 \cdot 10^{-7} C$

8 0

3 years ago

Read 2 more answers