Which temperature is lower ? -44°c -55°c

This is the solid outermost layer of the Earth, including the crust and upper-mantle.

mr_godi [17]

Together the crust and upper mantle are called the lithosphere

7 0

4 years ago

It is known that the gravitational force of attraction between two alpha particles is much weaker than the electrical repulsion.

natali 33 [55]

Answer:

The ratio of gravitational force to electrical force is 3.19 x 10^-36

Explanation:

mass of an alpha particle = 6.64 x $10^{-27}$ kg

charge on an alpha particle = +2e = +2(1.6 x $10^{-19}$ C) = 3.2 x $10^{-19}$ C

distance between particles = d

For gravitational attraction:

The force of gravitational attraction F = $\frac{Gm^{2} }{r^{2} }$

where G = gravitational constant = 6.67 x $10^{-11}$ m^3 kg^-1 s^-2

r = the distance between the particles = d

m = the mass of each particle

therefore, gravitational force = $\frac{6.67*10^{-11}*(6.64*10^{-27} )^{2} }{d^{2} }$ = $\frac{2.94*10^{-63} }{d^{2} }$ Newton

For electrical repulsion:

Electrical force between the particles = $\frac{-kQ^{2} }{r^{2} }$

where k is the Coulomb's constant = 9.0 x $10^{9}$ N•m^2/C^2

r = distance between the particles = d

Q = charge on each particle

therefore, electrical force = $\frac{-9*10^{9}*(3.2*10^{-19} )^{2} }{d^{2} }$ = $\frac{-9.216*10^{-28} }{d^{2} }$ Newton

the negative sign implies that there is a repulsion on the particles due to their like charges.

Ratio of the magnitude of gravitation to electrical force = $\frac{2.94*10^{-63} }{9.216*10^{-28} }$

==> 3.19 x 10^-36

8 0

3 years ago

The periodic table is an arrangment of the chemical elements, ordered by atomic number, into families, and by doing so illustrat

olya-2409 [2.1K]

Answer:

Option B) reactive to nonreactive

Explanation:

A) Solid to gas

This might apply, because most of the gases are to the right portion of the periodic table

There are just a few elements that are gases at room temperature; a total of 11: six noble gases (group 18), two halogens (group 17), oxygen (group 16), nitrogen (group 15), and hydrogen (group 1).

Hydrogen is an exception to this trend because they are in the left part of the periodic table.

B) Reactive to nonreactive

The most reactive metals are in group 1 (alkali metals) and the most reactive nonmentals are in the group 18 (halogens). Hence, it is false that the from left to right the preperties go from reactive to nonreactive.

Hence, this is the one that cannot apply.

C) Metal to metalloid to nonmetal

It is true that the metallic character of the elements decreases from left to right; the metals are to the left, going to the right you find some metalloids, and further to the right you find the nonmetals.

Hence, this trend is correct.

D) Increasing number of outer-shell electrons

The number of outer-shell electrons definetly increase from left to right.

The number of electrons in neutral atoms equals the number of protons (to balance the positive and negative charges). Since, the atomic number (the number of protons) increase from left to right, the number of electrons also increase.

In a period (a row of the periodic table) the electrons add to the same outer-shell, then you will find that the number of electrons of the outer-shell increase from left to right. Hence, this is also a correct trend.

In conclusion, the only trend that does not apply is the described by the option B).

4 0

3 years ago

Read 2 more answers

Please help, will give brainliest:

Genrish500 [490]

Answer:

v = 0.0251 km/h

Explanation:

Given that,

The average distance from its center of mass of 1000 meters.

The time taken is 24 hours and 57 minutes to complete one orbit

We need to find the orbital velocity of the spacecraft OSIRIS-REx.Let it is v. SO,

$v=\dfrac{2\pi r}{t}$

Putting all the values,

$v=\dfrac{2\pi \times 100}{24\ hours\ and\ 57\ minutes}\\\\v=\dfrac{2\pi \times 100}{(86400+3420)}\\\\v=0.00699\ m/s$

or

v = 0.0251 km/h

So, the average orbital velocity is 0.0251 km/h.

5 0

3 years ago

a stone of mass 750 kg is thrown vertically upward with a velocity of 10m/s find the potential energy at the greatest height and

Taya2010 [7]

Answer:

Potential Energy at the greatest point = 37.5 J

Explanation:

Given :

Mass is 750 g

In term of kg :

Mass is 0.75 kg .

Velocity ( v ) = 10 m / sec

We have formula for kinetic energy :

K.E. = 1 / 2 m v²

Putting values now :

K.E. = 1 / 2 × 0.75 × 10 × 10

K.E. = 1 / 2 × 75 J

K.E. = 37.5 J

Since K.E . = P.E.

Thus potential energy of stone is 37.5 J .

8 0

3 years ago

Which temperature is lower ? -44°c -55°c​

Which temperature is lower ? -44°c -55°c