A. helium, neon and argon, because they are in the same group or column
Answer:
0.826 g/cm³
Explanation:
density = mass/volume
density = 715 g/866 cm³
density = 0.82564 g/cm³
Rounded to 3 significant figures: 0.826 g/cm³
Answer: B) The fireworks give off heat
Complete balanced equation: 2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O
Ionized equation (with spectator ions):
2H⁺ + 2NO₃⁻ + Ca²⁺ + 2OH⁻ → Ca²⁺ + 2NO₃⁻ + 2H₂O
By eliminating the ions that are the same of both sides of the equation (spectator ions):
2H⁺ + 2OH⁻ → 2H₂O [Net Ionic Equation]
I believe the atomic level increases hope this helps.