B, because earths gravity if pulling on the moon and since velocity pulls it it’s like earth tied a string to the moon and the moon goes in a circle
Answer:
The correct answer is: X is nitrogen dioxide, and Y is a metal oxide
Explanation:
Combustion of compound of containing nitrogen and metal will give nitrogen dioxide and metal oxide as product. During combustion reaction a compound reacts with oxygen in order to yield oxides of elements present in the compound.
The general equation is given as:

Hence, the correct answer is :X is nitrogen dioxide, and Y is a metal oxide.
Answer:
The correct answer is - (Choice A) A Photosynthetic plants can move carbon from the atmosphere into an ecosystem’s food web.
Explanation:
Photosynthesis is the process performed by photosynthetic or green plants in presence of light atmospheric carbon dioxide and water converted into glucose (6 carbon compound) and oxygen.
This glucose or sugar is utilized by the plants that are producers in the ecosystem food web. These producers are fed by consumers and carbon molecules transfer from all the trophic levels in the food chain or food web in the process.
Answer is: coefficient is one.
Chemical reaction: SiO₂ + 4HF → SiF₄ + 2H₂O.
Reaction is balanced when there are equal numbers of elements in both side of the chemical reaction.
HF - hydrofluoric acid, <span>highly corrosive, dissolves many materials.</span>
SiF₄ - silicon tetrafluoride.