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3 years ago

Which of the following is the best definition of an element?

Physics

1 answer:

Ostrovityanka [42]3 years ago

8 0

Answer:

A. chemical substance whose atoms all have the same number of protons

Explanation:

An element is a substance which contains identical atoms that have the same number of protons in the nucleus.

Elements are arranged in the periodic table according to their atomic number (= number of protons): so atoms of different elements have a different number of protons in their nuclei.

For a neutral atom, the number of electrons around the nucleus is also equal to the number of protons.

Moreover, atoms of the same element can have a different number of neutrons, despite having the same number of protons - these atoms are called isotopes.

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Identify each unit as belonging to SI units or US Customary units.

torisob [31]

Answer:

SI Units

Meter

Kilogram

Kelvin

US Customary Units and English Units

Gallon

Mile

Pound

Degrees Fahrenheit

Explanation:

The SI units or International System of Units are the widely used metrics of measuring a physical quantity. It has specific abbreviations.

The US customary units is a measurement system where it is widely used in the united states. This system of unit also has abbreviations.

There are also conversion scales that are used to convert a unit from one metric system to the other.

For example, the conversion of mile to SI unit is given by the formula

1 mile = 1609.4 meters

Similarly,

1 pound = 0.453592 Kg

6 0

3 years ago

HELP What is the goal of a theory?

Dafna1 [17]

Hi,

The goal of a theory is to explain natural and physical phenomena.

Hope it helps you...

Pls mark brainliest if it helps you...

(Answered by Benjemin)

4 0

2 years ago

at which plate boundary would you expect to see volcanoes A.divergent b.all of the above c.convergent D.transform

natulia [17]

A or d would be most likely it

7 0

3 years ago

A mobile starts with a speed of 250m / s and begins to decelerate at a rate of 3m / s². How fast is it after 45s?

Korvikt [17]

$\large{ \underline{ \underline{ \bf{ \purple{Given}}}}}$

Speed of the mobile = 250 m/s
It starts decelerating at a rate of 3 m/s²
Time travelled = 45s

$\large{ \underline{ \underline{ \bf{ \green{To \: find}}}}}$

Velocity of mobile after 45 seconds

$\large{ \underline{ \underline{ \red{ \bf{Now, \: What \: to \: do?}}}}}$

We can solve the above question using the three equations of motion which are:-

v = u + at
s = ut + 1/2 at²
v² = u² + 2as

So, Here a is acceleration of the body, u is the initial velocity, v is the final velocity, t is the time taken and s is the displacement of the body.

$\large{ \bf{ \underline{ \underline{ \orange{Solution:}}}}}$

We are provided with,

u = 250 m/s
a = -3 m/s²
t = 45 s

By using 1st equation of motion,

⇛ v = u + at

⇛ v = 250 + (-3)45

⇛ v = 250 - 135 m/s

⇛ v = 115 m/s

✤ Final velocity of mobile = 115 m/s

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4 0

3 years ago

Can we see the back side of the moon from earth?

Olegator [25]

No. The moon always keeps the same side facing us. Its rotation and revolution periods are equal.

5 0

2 years ago

Read 2 more answers