Answer:
Those with 3 protons and 3 neutrons are known as the isotope lithium-6. Those with 3 protons and 4 neutrons are known as the isotope lithium-7.
Explanation:
Particle mass charge location
protons 1.673*10 ^ - 27 kg 1.6*10 ^ -19 C in the nucleus
neutrons 1.675*10 ^ - 27 kg 0 in the nucleus
electron 9.11 * 10 ^ - 31 kg -1.6 * 10 ^ - 19 C around the nucleus (orbitals)
Protons and neutrons have almost same masses. Mass of electrons is 1/1840 the mass of the protons.
Protons and electrons have the same magnitud of charge with different sign. Protons are positive and electrons are negative. Neutrons do not have charge.
Answer:
23.34 %.
Explanation:
- The percentage of water must be calculated as a mass percent.
- We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.
- <em>Atomic masses of the elements:</em>
Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.
- <em>Mass of the formula unit:</em>
Cd(NO₃)₂•4H₂O
mass of the formula unit = (At. mass of Cd) + 2(At. mass of N) + 10(At. mass of O) + 8(At. mass of H) = (112.411 g/mol) + 2(14.0067 g/mol) + 10(15.999 g/mol) + 8(1.008 g/mol) = 308.5 g/mol.
- <em> Mass of water in the formula unit:</em>
<em>mass of water</em> = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.
- <em>So, the percent of water in the compound = [mass of water / mass of the formula unit] × 100 = [(72.0 g/mol)/(308.5 g/mol)] × 100 = 23.34 %</em>
The elements on the periodic table are arranged in order, by increasing atomic number.<span />
Answer:
18
Explanation:
Sabemos que la fórmula química del agua es H2O.
Usando la información que; H = 1, O = 16, podemos calcular la masa molar del agua de la siguiente manera
[2 (1) + 16] = 18
Por tanto, la masa molar del agua es 18
