<span>The mass number of an ion is calculated by adding the neutrons and electrons together. In this case 159+107=266. However, since this ion has a +1 charge, you must add 1 to the electrons. This would give a total mass of 267.</span>
Answer:
B. choosing a material that will show warning before it fails.
Explanation:
Answer:
Bueno,
Explanation:
Tres pesnamientos negativos sobre el C0Vid-19 son,
- Encerrados en la casa
- Tener que ponerse mascara
- Todos los lugares divertidos cerrados
Convertidos en positivos:
- Pasamos mas tiempo de calidad en familia.
- Nos protejemos unos a otros.
- Descansan un poco todas las personas que se han pasado toda la vida trabajando.
Endothermic reaction is the answer.
Answer:
Explanation:
1) Chemical formula of sodium carbonate: <em>Na₂CO₃</em>
2) Ratio of carbon atoms:
- The number of atoms of C in the unit formula Na₂CO₃ is the subscript for the atom, which is 1 (since it is not written).
Hence, the ratio is 1 C atom / 1 Na₂CO₃ unit formula.
This is, there is 1 atom of carbon per each unit formula of sodium carbonate.
3) Calculate the number of moles in 1.773 × 10⁷ carbon atoms
- Divide by Avogadro's number: 6.022 × 10²³ atoms / mol
- number C moles = 1.773 × 10⁷ atoms / (6.022 × 10²³ atoms/mol)
- number C moles = 2.941 × 10⁻¹⁷ mol
Since, the ratio is 1: 1, the number of moles of sodium carbonate is the same number of moles of carbon atoms.
