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3 years ago

How can we describe an atom

2 answers:

7 0

The smallest unit of an element, consisting of at least one proton and (for all elements except hydrogen) one or more neutrons in a dense central nucleus, surrounded by one or more shells of electrons. In electrically neutral atoms, the number of protons equals the number of electrons.

Lana71 [14]3 years ago

4 0

In simple terms an atom is a cloud of tiny electrons buzzing round a central much larger nucleus in a series of orbits called shells.

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Which of the following affects the rate constant of a reaction?

Art [367]

A the entropy of the reaction I think ion know if that’s correct

3 0

2 years ago

Eukaryotic that can reproduce sexually contain two types of cells

Darina [25.2K]

Only eukaryotes form multicellular organisms consisting of many kinds of tissue made up of different cell types. Eukaryotes can reproduce both asexually through mitosis and sexually through meiosis and gamete fusion. In mitosis, one cell divides to produce two genetically identical cells.

7 0

3 years ago

What causes convection currents, and what do they do?

frez [133]

Answer:

Convection currents are the result of different heating. Lighter material (warm) rises while heavier (cold) material sinks. This movement of the materials is what causes convection currents! (BTW, it happens in water, in the atmosphere, and in the mantle of Earth!

Explanation:

I hope this helps a little! :)

6 0

3 years ago

A car accelerates uniformly from rest to speed 6.6 m/s in 6.5 s .Find the distance the car travel during this time .

kirill [66]

Answer:

The distance the car traveled is 21.45 m

Explanation:

Motion With Constant Acceleration

It occurs when an object changes its velocity at the same rate thus the acceleration is constant.

The relation between the initial and final speeds is:

$v_f=v_o+at\qquad\qquad [1]$

Where:

a = acceleration

vo = initial speed

vf = final speed

t = time

The distance traveled by the object is given by:

$\displaystyle x=v_o.t+\frac{a.t^2}{2}\qquad\qquad [2]$

Solving [1] for a:

$\displaystyle a=\frac{v_f-v_o}{t}$

Substituting the given data vo=0, vf=6.6 m/s, t=6.5 s:

$\displaystyle a=\frac{6.6-0}{6.5}$

$a = 1.015\ m/s^2$

The distance is now calculated with [2]:

$\displaystyle x=0*6.5+\frac{1.015*6.5^2}{2}$

x = 21.45 m

The distance the car traveled is 21.45 m

6 0

3 years ago

Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m^2. Assuming that all the photons in th

andrew11 [14]

Answer:

3.066×10^21 photons/(s.m^2)

Explanation:

The power per area is:

Power/A = (# of photons /t /A)×(energy / photon)

E/photons = h×c/(λ)

photons /t /A = (Power/A)×λ /(h×c)

photons /t /A = (P/A)×λ/(hc)

photons /t /A = (680)×(678×10^-9)/(6.63×10^-34)×(3×10^-8)

= 3.066×10^21

Therefore, the number of photons per second per square meter 3.066×10^21 photons/(s.m^2).

4 0

3 years ago