The answer is B. a flashlight uses a battery to operate.
The battery represents the chemical energy. This is converted into electricity, which is converted into light energy.
Atoms of elements that are nonmetals tend to gain electrons and atoms of metallic elements tend to lose electrons. Metals have few electrons in their valence shells.
By losing those electrons, these metals achieve noble gas configuration and satisfy the octet rule.
Nonmetals that have close to 8 electrons in their valence shells readily accept electrons to achieve noble gas configuration.
An example is the reaction between calcium and oxygen. Calcium is a metal and has 2 valence electrons. Oxygen is a nonmetal and has 6 valence electrons.
Calcium gives up its two valence electrons and oxygen accepts them and an ionic bond is established resulting in the formation of anew compound namely calcium oxide.
Answer:
Groups
Explanation:
Elements with the same number of valence electrons are found in the same column(group) of the Periodic Table.
Answer:
3.6 × 10²⁴ molecules
Explanation:
Step 1: Given data
Moles of methane (n): 6.0 moles
Step 2: Calculate the number of molecules of methane in 6.0 moles of methane
In order to convert moles to molecules, we need a conversion factor. In this case, we will use Avogadro's number: there are 6.02 × 10²³ molecules of methane in 1 mole of molecules of methane.
6.0 mol × 6.02 × 10²³ molecules/1 mol = 3.6 × 10²⁴ molecules
Answer:
Mass = 36 g
Explanation:
Given data:
Mass of water formed = ?
Mass of hydrogen = 4.04 g
Mass of oxygen = 31.98 g
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen:
Number of moles = mass/molar mass
Number of moles = 4.04 g/ 2 g/mol
Number of moles = 2.02 mol
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 31.98 g/ 32 g/mol
Number of moles = 1.0 mol
Now we will compare the moles of water with hydrogen and oxygen.
O₂ : H₂O
1 : 2
H₂ : H₂O
2 : 2
2.02 : 2.02
Number of moles of water formed by oxygen are less thus oxygen will limiting reactant.
Mass of water:
Mass = number of moles × molar mass
Mass = 2 mol × 18 g/mol
Mass = 36 g
