Because they usually are weak.
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Answer:
Explanation:
H = 1
C = 12
O = 16
Acetylene, HC≡CH = 2+24 = 26
H2O = 2 + 16 = 18
In XS oxygen, one HC≡CH yields one H2O
26 g HC≡CH ==> 18 g H2O
2000 g HC≡CH ==> 2000*18/26 g H2O = 1384.6154 g H2O
Answer:
this showed that the cathode rays traveled in straight line
Answer:

Explanation:
1. Write the balanced chemical equation.

2. Calculate the moles of HCOOH

3. Calculate the moles of NaOH.

4. Calculate the volume of NaOH

Answer:
Reflection takes place from the polished smooth surfaces
Explanation:
A vacuum does not refer to an opaque body. An opaque body does not allow light to pass through it while a vacuum is simply empty space without air.
A smooth polished surface often acts as a mirror, it is a good reflector of light.
The moon is a non luminous body in the sky. It merely reflects the light from the sun.
A Pinhole camera can not take pictures of moving objects because it only focuses on any image placed before it.
Shadows are not inverted, the always appear upright.