Answer: i think c
Explanation:QA: “What is ordinary glass made of ?”
Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.
“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C
Answer:
c) mutation and natural selection both cause changes in a population
Explanation:
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Mark me as brainliest
Answer:
upwards
downwards
Explanation:
Given:
weight of the person,
So, the mass of the person:
- Now if the apparent weight in the elevator,
<u>Then the difference between the two weights is :</u>
is the force that acts on the body which generates the acceleration.
Now the corresponding acceleration:
upwards, because the normal reaction that due to the weight of the body is increased here.
- Now if the apparent weight in the elevator,
<u>Then the difference between the two weights is :</u>
is the force that acts on the body which generates the acceleration.
Now the corresponding acceleration:
downwards, because the normal reaction that due to the weight of the body is decreased here.
Answer:
39 g H2O contains 1.3 ×1024molecules H2O.
Explanation: