Answer is: A. Chemical energy to electromagnetic energy and thermal energy.
Balanced chemical reaction: 2Mg(s) + O₂(g) → 2MgO(s) + energy.
This is chemical change (chemical reaction), because new substance (magnesium oxide MgO) is formed, the atoms are rearranged and the reaction is followed by an energy change (exothermic reaction because energy is released).
Chemical changes (chemical synthesis) is when a substance combines with another (in this example magnesium and oxygen) to form a new substance.
Bonds of two atoms of equal electronegativity are nonpolar covalent bonds.
Your second sentence is identical to the first sentence; I'll bet the second sentence is "Bonds between two atoms that are unequally electronegative are polar covalent bonds."
In nature, boron is monoatomic. Therefore, its formula is B.
On the other hand, fluorine is diatomic. Therefore, its formula is F2
Now, the basic unbalanced equation is:
B + F2 .........> BF3
Now, we need to balance this equation. As you can see, we have two fluorine moles entering the reaction and 3 formed in the products.
Balancing the equation, we will reach the following balanced reaction:
2B + 3F2 .......> 2BF3
Answer:
20.2 g silver placed in 21.6 mL of water and 20.2 g copper placed in 21.6 mL of water
Explanation:
Since the density formula is mass divided volume, you can calculate the density of each of the components of the group and see which of all the groups are equal
In the group
density Ag=20.2 g silver/21.6ml H2O=0.9352g/ml
density Cu=20.2 g copper/21.6ml H2O=0.9352 g/ml
At STP, also known as standard temperature and pressure, 1 mole of a gas occupies 22.4 L. Since we are given with the volume of 6.3L, we calculate the amount of gas in mol.
n = (6.3L)/ (22.4L/mol) = 0.28125 mol
We are given with the mass of 6.7 g. Therefore, the molar mass or molecular weight of the gas is equal to,
6.7g/0.28125 mol = 23.82 g/mol
