All categories

3 years ago

Over 100 existing elements are listed and classified on the ____________________.

2 answers:

8 0

Periodic table.

There is every element listed on the periodic table grouped and listed properly.

Hope this helps, let me know if you have questions. Have a great day!

Nadusha1986 [10]3 years ago

3 0

The answer is Periodic table

You might be interested in

Neutral atoms contain equal numbers of A protons and electrons. B protons and neutrons. C electrons and neutrons. D protons, ele

Verdich [7]

Answer:

For 1: The correct answer is Option A.

For 2: The correct answer is Option B.

For 3: The correct answer is Option C.

Explanation:

For 1:

Atomic number is defined as the number of electrons or number of protons that are present in a neutral atom. It is represented as Z.

Z = Atomic number = Number of electrons = Number of protons

Mass number is defined as the sum of number of protons and number of neutrons present in an atom. It is represented as A.

A = Mass number = Number of protons + Number of neutrons

Hence, the correct answer is Option A.

For 2:

The isotopic representation of an atom is: $_Z^A\textrm{X}$

where,

Z = Atomic number of the atom

A = Mass number of the atom

X = Symbol of the atom

We are given:

An isotopic representation of beryllium atom: $_4^9\textrm{Be}$

Thus, the number '4' represents the atomic number of beryllium, number '9' represents the mass number of beryllium atom.

Hence, the correct answer is Option B.

For 3:

In CO compound:

Mass of oxygen = 16 g

Mass of carbon = 12 g

In $CO_2$ compound:

Mass of oxygen = 32 g

Mass of carbon = 12 g

Thus, the ratio of mass of oxygen in $CO_2$ and CO is:

$CO_2:CO=32:16=2:1$

Hence, the correct answer is Option C.

3 0

3 years ago

What do scientists use scientific notation for?

tamaranim1 [39]

Scientists use scientific notation to simplify numbers, basically. When dealing with really big numbers or really small numbers, the usage of scientific notation prevents them from having to write a bunch of zeroes.
Hope that helped you!

8 0

3 years ago

Read 2 more answers

How many carbon atoms are represented by the model below A) 0 B) 3 C) 2 D) 1

Bogdan [553]

Answer:

Option (B) 3.

Explanation:

In the model represented above, the two extreme represent carbon atoms since no other group are attached to it. The joint at the middle also represent carbon atom.

Thus, we can write a more simplify illustration for the model above as

C—C—C

From the above illustration, we can see that the model contains 3 carbon atom.

5 0

2 years ago

How many Mg atoms are presented in 3.00 moles of MgCl2

ella [17]

Answer:

1.81 x 10²⁴ atoms

Explanation:

To find the number of atoms in the given number of moles, we need to understand that every substance contains the Avogadro's number of particles.

More appropriately, a mole of any substance will contain the Avogadro's number of particles which is 6.02 x 10²³ atoms

So;

If 1 mole of a substance = 6.02 x 10²³ atoms;

3 mole of MgCl₂ will contain 3 x 6.02 x 10²³ = 1.81 x 10²⁴ atoms

3 0

3 years ago

Help pleaseee

marissa [1.9K]

Answer:

In order to find the molecular formula from an empirical formula you must find the ratio of their molecular masses.

We know that the molecular mass of the molecule is 70

gmol-1

. We can calculate the molar mass of

CH2

from the periodic table:

C=12.01

gmol−1

H=1.01

gmol−1

CH2 =14.03

gmol−1

Hence we can find the ratio:

14.03

≈

0.2

6 0

3 years ago