Answer:
The corona shines only about half as brightly as the Moon and is normally not visible to the unaided eye, because its light is overwhelmed by the brilliance of the solar surface. During a total solar eclipse, however, the Moon blocks out the light from the photosphere, permitting eye observations of the corona.
Answer:
a minimum of <em>1</em><em>0</em><em>,</em><em>0</em><em>0</em><em>0</em><em> </em>years
Answer:
Option d. 7
Explanation:
A mixture of a strong base and a strong acid produce a neutral salt and water.
This is the reaction of neutralization:
HCl + NaOH → NaCl + H₂O
NaCl → Na⁺ + Cl⁻
Sodium chloride is neutral salt which does not give H⁻ neither OH⁻ to medium, that's why pH is neutral.
Both ions are derivated from a strong acid and base so they do not make hydrolisis. They are a conjugate pair of a weak acid and base. The reactions can not occur:
Cl⁻ + H₂O ← OH⁻ + HCl
Na⁺ + H₃O⁺ ← NaOH + H₂O
Answer:
Calcium would displace barium.
Explanation:
Ba(NO₃)₂ + Ca --> Ca(NO₃)₂ + Ba
There are two types of compounds: molecular/covalent and ionic.
Molecular/covalent compounds are non-metal + non-metal.
Ionic compounds are metal + non-metal.
Looking at the periodic table, barium is a metal. Calcium is also a metal.
Checking a polyatomic ions chart would tell you NO₃⁻ is a non-metal because it has a negative charge.
Since there is no metal + metal compound, the calcium metal would displace barium. The compound remains ionic.
