B. because the other options are different sciences (biology and entomology)
Answer:
118201.68m6^2
Explanation: scientific notation
Answer:
Partial pressure of oxygen = 190 mmHg
Explanation:
From the question;
Mixture contains only nitrogen and oxygen
Total pressure of the mixture = 480 mmHg
Partial pressure of nitrogen = 290 mmHg
Dalton's law states that the pressure of a system is as a result of the sum of the partial pressures of the individual components of the mixture. This means that in this mixture;
Pressure of mixture = Partial Pressure of Nitrogen + Partial Pressure of Oxygen
480 = 290 + Partial pressure of oxygen
Partial pressure of oxygen = 480 - 290
Partial pressure of oxygen = 190 mmHg
Answer:
Se⁻²
Explanation:
Even though the atom is not shown, we can consult the periodic table. Selenium (Se) is in group 6 and period 4, so it has 6 valence electrons. To be stable, the atom must have a noble gas configuration with 8 valence electrons, thus, selenium must gain 2 electrons.
When an atom gain electrons, it is negatively charged, because electrons have a negative charge. So, the ion formed is Se⁻².