Answer:
...a force acts upon it.
Explanation:
"An object in motion tends to stay in motion unless a force acts upon it."
This same rule implies to running water. Water typically runs from a higher place to a lower place with the usage of gravity (except for certain rare cases). Until there is something blocking (for example, a dam, or a let down in the steepness of the drop), the water will continue to move forward.
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Answer:
Organ level– an organ is a structure composed of at least two different tissue types that perform a specific function within the body. Examples include the brain, stomach, and liver. Complex functions begin to emerge at this level.
Explanation:
Answer:
c. the gravitational forces due to the sun and the moon cancel each other's effect
Explanation:
The two diagrams represent Neap tides. Neap tides occur when the Sun, the Moon and the Earth are aligned at right angles. Moderate tides are formed because the bulge due to gravitational pull of the Sun cancels the bulge due to moon. The difference between the high tides and the low tides is the smallest.
Water has special characteristics because liquid water is denser than ice and ice floats on top of liquid water.
Answer: Option A & D
<u>Explanation:</u>
A water molecule is formed by the covalent bonding between two atoms of Hydrogen atom with one atom of Oxygen. In water, the Hydrogen bonds are the one that keeps the water molecule intact.
When the water molecule freezes the bonding becomes weak as they are separated and set apart which makes the liquid water denser than ice. Normally a substance floats if it is less dense. Ice floats because it is less dense than water.
Answer:
Explanation:
Oxygen gas and water must be present for iron to rust.
A region of the metal’s surface serves as the anode, where oxidation
occurs:
Fe(s) → Fe²⁺ (aq) + 2 e⁻
The electrons given up by iron reduce atmospheric oxygen to water at the cathode, which is another region of the same metal’s surface:
O₂ (g) + 4H⁺ (aq) + 4 e⁻ → 2 H₂O (l)
The overall redox reaction is:
2 Fe(s) + O₂(g) → 4H⁺(aq) + 2Fe²⁺ (aq) + 2 H₂O(l)
The Fe²⁺ ions formed at the anode are further oxidized by oxygen:
4 Fe²⁺ (aq) + O₂(g) 1 (4 + 2x) H₂O (l) → 2 Fe₂O₃ . xH₂O(s) + 8 H⁺(aq)
This hydrated form of iron(III) oxide is known as rust. The amount of water associated with the iron oxide varies, so we represent the formula as 2 Fe₂O₃ . xH₂O.
