Answer:
The elements of the same group have the same number of valence electrons, that is why they have similar properties
The chemical at the heart of the air bag reaction is called sodium azide, or NaN3. CRASHES trip sensors in cars that send an electric signal to an ignitor. The heat generated causes sodium azide to decompose into sodium metal and nitrogen gas, which inflates the car's air bags.
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4 significant figures. Use a rule called the Atlantic-Pacific rule where if the period is absent (Atlantic), you would start counting the numbers from right to left. If the period is present (Pacific), then start counting the numbers from left to right. Since the period is present, start from 5 and there are 4 digits including 5.