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Kazeer [188]
3 years ago
7

Why does an exothermic reaction need activation energy?

Chemistry
1 answer:
andrey2020 [161]3 years ago
6 0

Answer:

Activation energy is needed so reactants can move together, overcome forces of repulsion, and to begin breaking bonds.

Explanation:

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A large room contains moist air at 308C, 102 kPa. The partial pressure of water vapor is 1.5 kPa. Determine
andreev551 [17]

Answer:

you tell me

Explanation:

4 0
2 years ago
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
Which statement is true about intermolecular forces?
seropon [69]

Answer:

Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.

Importance:

Intermolecular forces are important because they determine the physical properties of substances. Many of the life-sustaining properties of water such as its high heat capacity are a result of the hydrogen bonding capabilities it has and are thus due to intermolecular forces.

4 0
2 years ago
Helooo i need help please :)
Tatiana [17]
It is a ,d and c just make sure tho
6 0
2 years ago
Hydrocarbons separated by fractional distillation of petroleum can be cracked to make
lana66690 [7]

Answer:

c.hg cannot be cracked for fractional distillation as there is only one of each

Explanation:

8 0
2 years ago
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