Ask question

Ask question

All categories

3 years ago

15

Of the eight most abundant elements in earths crust, what percentage does the six next most abundant elements of earths crust ma

ke up?

1 answer:

Mrac [35]3 years ago

5 0

Answer:

the sixth most abundant element in the earth's crust is sodium and it occupies 2.8%

You might be interested in

Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Which statement describes the subscripts she will

STALIN [3.7K]

Answer:

She will use one 2 as a subscript.

Explanation:

Nitrogen is a chemical element with the symbol "N" and has an atomic number of 7. Thus, it is found in group (5) of the periodic table and as such it has 5 electrons in its outermost shell. Therefore, nitrogen has two (5) valence electrons.

On the other hand, oxygen has an atomic number of 8 and with the symbol "O."

When nitrogen and oxygen react chemically, they produce a compound known as nitrogen dioxide $NO_{2}$

In this scenario, Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Therefore, the statement which describes the subscripts she will use to write the chemical formula is, she will use one 2 as a subscript.

$N + O_{2} ------> NO_{2}$

Where: 2 represents the subscript of oxygen.

7 0

2 years ago

A horse of mass 242 kg pulls a cart of mass 224 kg. The acceleration of gravity is 9.8 m/s 2 . What is the largest acceleration

Rufina [12.5K]

To solve this problem it is necessary to apply the concepts related to Newton's second Law and the force of friction. According to Newton, the Force is defined as

F = ma

Where,

m= Mass

a = Acceleration

At the same time the frictional force can be defined as,

$F_f = \mu N$

Where,

$\mu =$ Frictional coefficient

N = Normal force (mass*gravity)

Our values are given as,

$m_h = 242 kg\\m_c = 224 kg\\\mu = 0.894\\$

By condition of Balance the friction force must be equal to the total net force, that is to say

$F_{net} = F_f$

$m_{total}a = \mu m_hg$

$(m_h+m_c)a = \mu*m_h*g$

Re-arrange to find acceleration,

$a= \frac{\mu*m_h*g}{(m_h+m_c)}$

$a = \frac{0.894*242*9.8}{(242+224)}$

$a = 4.54 m/s^2$

Therefore the acceleration the horse can give is $4.54m/s^2$

3 0

2 years ago

How can isotopes of a given element be identified?

marin [14]

Answer: All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. ... Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons.

Explanation: Hopefully this helps. Have a great day.

6 0

2 years ago

When an electron is added to a neutral atom of an element to form a negative ion, the resulting change in energy is referred to

IgorLugansk [536]

The statement "<span>When an electron is added to a neutral atom of an element to form a negative ion, the resulting change in energy is referred to as the electron potential of that element." is false.

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.
</span>

4 0

3 years ago

What event, which occurs twice a year when the sun crosses Earth's equator, recently

andrey2020 [161]

Answer:

<u>the autumnal equinox (when day and night are of equal length)</u>

<u>Explanation:</u>

The first event occurs around the 22nd or 23rd in the month of September. What usually happens is that regions around the Northern Hemisphere (which includes all of North America and Europe) experience an equal length of day and night.

While the second event occurs around March 20th or 21st mainly observable in countries found in the Southern Hemisphere.

5 0

3 years ago