Answer:
B. The substance is in the liquid state.
Explanation:
The symbol (l) in a chemical equation represents that the substance is in liquid state which is one of the physical states of a chemical substance.
Answer:
0.504 M
Explanation:
Step 1: Write the balanced neutralization reaction
2 KOH + H₂SO₄ ⇒ K₂SO₄ + 2 H₂O
Step 2: Calculate the reacting moles of KOH
55.2 mL (0.0552 L) of 0.500 M KOH react. The reacting moles of KOH are:
0.0552 L × 0.500 mol/L = 0.0276 mol
Step 3: Calculate the moles of H₂SO₄ that reacted with 0.0276 moles of KOH
The molar ratio of KOH to H₂SO₄ is 2:1. The reacting moles of H₂SO₄ are 1/2 × 0.0276 mol = 0.0138 mol
Step 4: Calculate the concentration of H₂SO₄
0.0138 moles of H₂SO₄ are in 27.4 mL (0.0274 L). The molarity of H₂SO₄ is:
[H₂SO₄] = 0.0138 mol/0.0274 L = 0.504 M
1) Atomic number of magnesium (Mg) is 12, it means that it has 12 protons and 12 electrons.
Electron configuration of magnesium atom: ₁₂Mg 1s² 2s² 2p⁶ 3s².
2) Atomic number of aluminium (Al) is 13, it means that it has 13 protons and 13 electrons., but if it lost one electron, it will have 12 electrons and 13 protons and become aluminium cation Al⁺.
Electron configuration of aluminium cation: ₁₃Al⁺ 1s² 2s² 2p⁶ 3s².
3) Atomic number of silicon (Si) is 14, it means that it has 14 protons and 14 electrons., but if it lost two electrons, it will have 12 electrons and 14 protons and become silicon cation Si²⁺.
Electron configuration of silicon cation: ₁₄Si²⁺ 1s² 2s² 2p⁶ 3s².
<span>Neutrons.
The nucleus of an atom contains two kinds of particles, protons and neutrons. The number of protons determines what element the atom is. Atoms that have the same number of protons but different numbers of neutrons are isotopes of the same element.
For example, if two atoms both have 1 proton in their nuclei, but one atom has 0 neutrons and the other has 1 neutron, both atoms are hydrogen but they are different isotopes of hydrogen.</span>
