Which solid from the table is the most dense ? please help

Consider the following isotopic symbol: 137Ba2+

aliya0001 [1]

Answer:

a) 56 protons

b) 54 electrons

c) 81 neutrons

d) The sum of protons and neutrons is shown. The number of protons is always the same. So we can calculate the number of neutrons ( and also the isotopes)

e)137Ba (with 56 protons and 81 neutrons)

f) atomic mass is 136.9 u ; the mass number is the sum of protons and neutrons and is 137

Explanation:

Step 1: Data given

137 Ba2+ is an isotope of barium. The atomic number of barium( and its isotopes) is 56. This shows the number of protons.

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

The different isotopes of an element have the same number of protons but a different number of neutrons.

137Ba2+ has 56 protons (this is the same as the atomic number)

137Ba2+ has 54 electrons ( since it's Ba2+, this means it has 2 electrons less than protons, that's why it's charged +2)

137Ba2+ has 81 neutrons ( 137 - 56 = 81)

In the symbol, the atomic number is not shown. The sum of the protons and neutrons is shown. (Since the number of protons is the same for every isotope, we can calculate the number of neutrons that way. By knowing the neutrons, we also know the isotope.

This isotope is 137Ba

Atomic mass is also known as atomic weight. The atomic mass is the weighted average mass of an atom of an element based on the relative natural abundance of that element's isotopes.

The atomic mass of 137Ba2+ is 136.9 u

The mass number is a count of the total number of protons and neutrons in an atom's nucleus.

The mass number of 137Ba2+ is 137

3 0

3 years ago

Consider the following system at equilibrium:

elena-14-01-66 [18.8K]

Answer:

Increase D ⇒ rightward shift

Increase E ⇒ rightward shift

Increase F ⇒ leftward shift

Decrease D ⇒ leftward shift

Decrease E ⇒ leftward shift

Decrease F ⇒ rightward shift

Triple D and reduce E to one third ⇒ no shift

Triple both E and F ⇒ no shift

Explanation:

Changes in the concentrations of reactants y products affect to the equilibrium. In this case, D and E are reactants and F is the product.

When a change in the factors affecting equilibrium occur, the system will react in order to counteract the change imposed.

If a increase of reactant occur, the system will tend to produce more products (rightward shift). For example: increase D, increase E. In contraposition, if a decrease of reactant occur, the system will produce more reactants (leftward shift). For example: decrease D, decrease E.

If a increase of product occur, the system will tend to produce more reactants (leftward shift). For example: increase F. In contraposition, if a decrease of product occur, the system will produce more products (rightward shift). For example: decrease F.

If we change both reactants and products concentration in the same amount, the net change is zero, so there is not shift. For example: Triple D and reduce E to one third (D x 3 and E/3, there is not change in the total amount of reactants) ; Triple both E and F (E x 3 and F x 3, the net change is zero).

8 0

3 years ago

Describe what happens to the size of atoms of the elements as you go across a row and down a column in the periodic table. expla

ipn [44]

Atom size increases down a group because there is an increase in the number of shells so the attraction between electrons and protons decreases. Atom size decreases across a period because the number of protons increases meaning that there is more attraction between the protons and electrons therefore drawing the outer shells closer to the nucleus.

8 0

3 years ago

In the following reaction, what coefficient will be written before the potassium nitrate (KNO3 ) to balance the chemical equatio

puteri [66]

Hey there:

Balanced chemical equation:

1 K2CrO4 + 1 Pb(NO3)2 = 2 KNO3 + 1 PbCrO4

Coefficients : 1 , 1 , 2 , 1

hope this helps!

4 0

3 years ago

What is a metabolic pathway? What is a metabolic pathway?

kotykmax [81]

Answer:

B) A series of chemical reactions where enzymes work one at a time to convert a reactant into intermediates and the intermediates into a final product.

Explanation:

In our cells there are multiple chemical reactions happening all the time to convert the elements we ingest (food, water, air) into the products the organism needs.

This processes can be very complex and offen involves various reactions (steps). Also, many of this reactions need to by catalized by enzymes in order to happen.

8 0

3 years ago

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