Answer:
The warmer, lighter air rises, bringing cooler, heavier air to low altitudes.
Air at higher altitudes doesn't have as much air weighing down on it from above.
Explanation:
In short - air pressure is the result of the cumulative force that air molecules act on objects below them due to Earth's gravity. The higher the altitude, the less air molecules there are to act a force below them, and therefore, there's less air pressure at higher altitudes.
D. a compound can only be separated into its components by chemical means
Answer:
0.0468 g.
Explanation:
- The decay of radioactive elements obeys first-order kinetics.
- For a first-order reaction: k = ln2/(t1/2) = 0.693/(t1/2).
Where, k is the rate constant of the reaction.
t1/2 is the half-life time of the reaction (t1/2 = 1620 years).
∴ k = ln2/(t1/2) = 0.693/(1620 years) = 4.28 x 10⁻⁴ year⁻¹.
- For first-order reaction: <em>kt = lna/(a-x).</em>
where, k is the rate constant of the reaction (k = 4.28 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = t1/2 x 8 = 1620 years x 8 = 12960 year).
a is the initial concentration (a = 12.0 g).
(a-x) is the remaining concentration.
∴ kt = lna/(a-x)
(4.28 x 10⁻⁴ year⁻¹)(12960 year) = ln(12)/(a-x).
5.54688 = ln(12)/(a-x).
Taking e for the both sides:
256.34 = (12)/(a-x).
<em>∴ (a-x) = 12/256.34 = 0.0468 g.</em>
Ionic compounds are formed by the complete transfer of electrons from more electronegative elements to less electronegative elements.
7. <u>Sodium Nitride (Na₃N)</u> is an ionic substance.
8. The ionic formula for <u>Lithium Oxide is Li₂O</u>
9. The <u>compound SrF₂</u>
10. Aluminum Sulfide is a chemical compound with the <u>formula Al₂S₃.</u>
An ionic compound is a chemical compound composed of ions held together via electrostatic forces termed ionic bonding. The compound is neutral standard but includes definitely charged ions known as cations and negatively charged ions known as anions.
An ionic compound is a chemical compound composed of ions held collectively by means of electrostatic forces termed ionic bonding. The compound is neutral normal however consists of positively charged ions known as cations and negatively charged ions referred to as anions. Ionic compounds incorporate ions and are held collectively via the attractive forces of most of the oppositely charged ions.
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