Answer:
2Al+ 6HNO3 ---- 3H2 + 2Al(NO3)3
Explanation:
Put coefficient a,b,c, and d for calculation:
a Al + b HNO3 = c H2 + d Al(NO3)3
for Al: a = d
for H: b = 2c
for N: b = 3d
for O: 3b = 9d
Suppose a=1, then d=1, b=3, c=3/2
multiply 2 to make all natural number, a=2, then b=6, c=3, d=2
A) c = 3 x 10^8 m/s
f = 7.15 x 10^14 Hz
c = λ x f (=) λ = 3 x 10^8 / 7.15 x 10^14 = 4.19 x 10^-7 m = 419.6 nm
B) E = h f
H = Planck's constant = 6.63 x 10^-34 J/s
E = 6.63 x 10^-34 x 7.15 x 10^14 = 4.74 x 10^-19 J
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The metalloids are mostly concentrated in groups 14, 15, and 16. (Some simpler charts will show them as 4A, 5A, and 6A - take a look at the top of the periodic table your class uses to double-check).
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To help plan for likely weather events.
<h3>
Answer:</h3>
22.41 seconds longer
<h3>
Explanation:</h3>
- Sound is a longitudinal wave that requires a material medium for transmission hence called a mechanical wave.
- Examples of medium in which sound travels in are water and air.
From the question give;
Speed of sound in air at 20°C is 343 m/s
Speed of sound in water at 20°C is 1,483 m/s
We are given a distance of 10 Km or 10,000 m
We need to finder how much longer it will take for the sound to travel in air.
Time = Distance ÷ Speed
Therefore;
Time taken in Air = Distance ÷ speed of sound in air
= 10000 m ÷ 343 m/s
= 29.15 seconds
Time taken in water = Distance ÷ speed of sound in water
= 10,000 ÷ 1,483 m/s
= 6.74 seconds
Difference in time = 29.15 seconds - 6.74 seconds
= 22.41 seconds
Therefore, it takes 22.41 seconds longer for sound to travel through air than water.