<span>Hydrogen isn't classified as an alkali metal because it exhibits several properties that are not found in the alkali metal group, including the tendency to be found as a diatomic molecule, a tendency to form weak bonds with other bound hydrogen atoms nearby, weak electromagnetism, a low activity series placement, and the tendency to be found as a gas. Because of all this, it's impossible to classify it with any group, although it does seem to be closest to nonmetals.</span>
Answer:
This question is incomplete
Explanation:
This question is incomplete.
However, when all the required data are available, you can use the formula/steps below
Average speed/velocity (m/s) = distance (in metres) ÷ time (in seconds)
Time (in secs) = distance ÷ average speed/velocity
Kindly note that "blocks" is not a standard unit for distance measurement in science, hence the distance (since its a walking distance) must be in metres (or converted to metres if not in metres).
The distance in the formula is the distance from the hotel to the ice cream shop while the average speed is the distance covered per time as s/he walks to the ice cream shop and back. Hence, the answer gotten from the formula above will have to be multiplied by 2 (in order to get the time taken to walk to the ice cream shop and back) because the formula will only provide answer to one trip (time taken to walk to the shop).
After the multiplication mentioned above, the time in seconds should be converted to minutes by dividing the answer in seconds by 60
Answer:
1. Main sequence stars have different masses. The common characteristic they have is their source of energy. They burn fuel in their core through the process of fusing hydrogen atoms into helium.
2. Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between about −3 and −8. The temperature range of supergiant stars spans from about 3,400 K to over 20,000 K.
3. Supergiants develop when massive main-sequence stars run out of hydrogen in their cores.
4. a supernova occur When the pressure drops low enough in a massive star, gravity suddenly takes over and the star collapses in just seconds. This collapse produces the explosion.
5. when a star has reached the end of its life and explodes in a brilliant burst of light
Explanation:
Answer:
Explanation: A yellow precipitate o lead iodide is formed. see equation of reaction below: 
→ 
Th PbI2 is the insoluble yellow precipitate
