Answer:
Check the electronic configuration of elements.
Explanation:
▪Valence electrons are the elwctrons present in the outermost shell of any element.
For example,
Electronic Configuration of Sodium = 2,8,1
Here , Sodium has 1 valence electrons.
▪Valency of an element is the total no. of electrons to be gained/losed in order to achieve duplet/octate state.
For example,
Electronic configuration of Sodium = 2,8,1
Sodium can achieve octate state either by losing 1 electron or gaining 7 electrons. But losing 1 electron is eay than gaining 7 electrons. So Valency of Sodium = +1
☆Metals have 1 or 2 or 3 valence electrons.
☆Non metals have 4 or 5 or 6 or 7 valence electrons.
☆Noble gases tend to stay in duplet/octate state i.e they have 2 or 8 valence electrons.
Answer:
Explanation:
Building Vocabulary
Match each term with its definition by writing the letter of the correct definition on
the line beside the term in the left column.
5. nucleus b
6. proton f
7. neutron h
8. electron d
9. atomic number g
10. isotopes c
11. mass number a
12. energy level e
a. the sum of protons and neutrons in the nucleus of an
atom
b. the very small center core of an atom
c. atoms of the same element that differ in the number
of neutrons, but have the same number of protons
d. the particle of an atom that moves rapidly in the
space outside the nucleus
e. a specific amount of energy related to the movement
of electrons in atoms
f. the particle of an atom with a positive charge
g. the number of protons in the nucleus of every atom
of an element
h. the particle of an atom that is neutral
-. mass number a.
12. energy level e
C.Pennsylvania Titusville is in the state of Pennsylvania
Answer:
Endothermic reaction chemical equation
Reactnt A + Reactant B + Heat (energy) ⇒ Products
Exothermic reaction chemical equation
Reactnt A + Reactant B ⇒ Products + Heat (energy)
Explanation:
Endothermic Reaction
An endothermic reaction is a reaction that reaction that requires heat before it would take place resulting in the absorption of heat from the surrounding that can be sensed by the coolness of the reacting system
An example of an endothermic reaction is a chemical cold pack that becomes cold when the chemical and water inside it reacts
Exothermic Reaction
An exothermic reaction is one that rekeases energy to the surroundings when it takes place. This is as a result of the fact that the combined heat energy of the reactants is more than the chemical heat energy of the products. An example of an exothermic reaction is a burning candle
Answer: 8.691 mols of CO₂
Explanation:
To find the number of moles in a given grams, you want to use the molar mass.
Let's first find the molar mass of CO₂.
Carbon's molar mass is 12.011 g/mol
Oxygen's molar mass is 15.999 g/mol
To find molar mass of CO₂, we want to add up the molar mass of carbon and oxygen. Remember, there are 2 Oxygens so we need to mulitply that by 2.
12.011+2(15.999)=44.009 g/mol
Now that we have molar mass, we can convert 382.5 g to mols.
There are about 8.691 mols of CO₂.
