According to Kepler's second law of orbital motion, a plane's orbital speed changes , depending on how far it is from the sun. The closer a planet is to the sun, the stronger the sun's gravitational pull on it, and the faster the planet moves. The farther away from the sun, the weaker the sun's gravitational pull and the slower it moves in its orbit.
The orbit of a planet around the sun is not a perfect circle, but an ellipse - a flattened circle.
<u>Answer:</u>
<u>For 1:</u> Neutralization reaction
<u>For 2: </u>Zinc is more reactive than lead and less reactive than calcium.
<u>Explanation:</u>
When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

where,
Metal A is more reactive than metal B
The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.
From the reactivity series below,
Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.
While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.


Answer:
They have fewer hydrogen atoms attached to the carbon chain than alkanes
Explanation:
Let's compare ethane (an alkane) with ethene (an alkene) and ethyne (an alkyne):
- Ethane's formula is C₂H₄, while ethene's is C₂H₄ and ethyne's C₂H₂.
As you can see, alkenes and alkynes have fewer hydrogen atoms attached to the carbon chain due to them having multiple bonds between the carbon atoms.
Answer:
The fact that most alpha particles went straight through the foil is because the atom is mostly empty space.
Those that passed straight through did so because they didn't encounter any nuclei.
Explanation: