Answer:
<h2>
total no. of electron present in Valency shell is called valency electron </h2><h2>___________________</h2>
<h2>valency shell is that in which last electron is present</h2>
They can form acids or ‘acid rain’ like nitric acid or sulfuric acid which can damage buildings and structures.
Answer:
An open system can exchange both energy and matter with its surroundings. The stovetop example would be an open system, because heat and water vapor can be lost to the air.
Explanation:
Number 4 is Global Warming
Answer:
the correct answer is going to be the school