The answer to this question is toaster, it starts as electric, then heats up and turns to heat energy to heat up your food.
Answer:
d. The formation of a covalent bond between two amino acids
Explanation:
In a chemical reaction, a substance transforms into another with different chemical properties and a different formula. Bonds are created and/or destroyed. It must obey the law of conservation of mass and the law of conservation of elements.
<em>Which of the following is a chemical reaction?</em>
<em>a. Making a hydrogen bond between a water molecule and a sugar molecule. </em>NO. This is a physical change in which sugar dissolves in water but both their chemical identities remain the same. The hydrogen bond is a force of attraction and not a real bond in which electrons are gained, lost or shared.
<em>b. The melting of ice.</em> NO. This is a physical change. Solid water turns into liquid water but the identity of the molecules is the same.
<em>c. Changing a carbon atom to a nitrogen atom by radioactive decay.</em> NO. This is a nuclear reaction in which a new element appears but it is not a chemical reaction because it does not fulfill the law of conservation of elements.
<em>d. The formation of a covalent bond between two amino acids.</em> YES. A new bond is created and a protein dimer is formed.
The balanced equation for the reaction is as follows
Cu₂O + 2HCl ---> 2CuCl + H₂O
Molar ratio of Cu₂O to CuCl is 1:2
mass of Cu₂O reacted - 73.5 g
Number of moles of Cu₂O reacted - 73.5 g / 143 g/mol = 0.51 mol
According to the molar ratio,
when 1 mol of Cu₂O reacts then 2 mol of CuCl is formed
therefore when 0.51 mol of Cu₂O reacts then - 2 x 0.51 mol of CuCl is formed
number of CuCl moles formed - 1.02 mol
mass of CuCl formed - 1.02 mol x 99 g/mol = 101 g
mass of CuCl formed is 101 g
atomic number = number of protons
number of protons = number of electrons
So, number of electrons = 5
So, electron configuration = 2, 3
So, its valency = 3
Answer: 2.43 x 10^23 molecules
Explanation:
Molar mass of H2S: 2(1.008) + 32.06 = 34.1 g/mole
Avogadro’s number for converting moles to atoms or molecules: 6.02 x 10^23
(13.751375g H2S)(1 mole H2S)(6.02x10^23 molecules) / (34.1g/mole H2S)(1mole H2S) = 2.43 x 10^23 molecules H2S