I believe your answer would be the first one
hope this helps
1) 1 molecules
2) 2 oxygen atoms
3)2 moles of Al2O3 are formed
4)4:3
1. 
- The changing of liquid to a gas.
2. 
- The major source of pollution.
3. 
- Carbon dioxide and water vapor trapping heat given off by Earth.
4. 
- Layer absorbing ultraviolet rays.
5. 
- The changing of a gas to a liquid.
6. 
- Layer responsible for reflecting radio waves.
7. 
- The layer in which weather changes.
Answer:
What is the net ionic equation for a reaction between HCl and NaOH?
Explanation:
A salt is a neutral ionic compound. Let's see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is: NaOH + HCl → H2O and NaCl
Hope that helped.
Answer:
frequency = 0.47×10⁴ Hz
Explanation:
Given data:
Wavelength of wave = 6.4× 10⁴ m
Frequency of wave = ?
Solution:
Formula:
Speed of wave = wavelength × frequency
Speed of wave = 3 × 10⁸ m/s
Now we will put the values in formula.
3 × 10⁸ m/s = 6.4× 10⁴ m × frequency
frequency = 3 × 10⁸ m/s / 6.4× 10⁴ m
frequency = 0.47×10⁴ /s
s⁻¹ = Hz
frequency = 0.47×10⁴ Hz
Thus the wave with wavelength of 6.4× 10⁴ m have 0.47×10⁴ Hz frequency.
