The answer is (3). The powdered iron and the piece iron is the same substance and is just different in the shape. So the reason is the power has larger surface area for reaction occurs.
Answer:
abiotic components are non-living chemical and physical factors in the environment which affect ecosystems. Biotic describes a living component of an ecosystem
Explanation:
Answer:
In system A: A gas and a solid react to form a new solid product. the system entropy decreases.
In System B: Rubbing alcohol evaporates on the skin. liquid alcohol is converting to gas by evaporation so the system entropy increases.
Explanation:
Entropy is a thermodynamic quantity measure the degree of disorder of a certain system.
Gases have larger entropy compared to liquids which is larger than solids.
================================================================
(A) When a gas convert to a solid, its entropy decreases. ... because solids have less energy and entropy than solids.
So, in system A: A gas and a solid react to form a new solid product. the system entropy decreases.
================================================================
(B) Any chemical reaction that increases the number of gas molecules also increases entropy.
So, in System B: Rubbing alcohol evaporates on the skin. liquid alcohol is converting to gas by evaporation so the system entropy increases
================================================================
Car: (convert first the units)
240 km * (1000 m /1 km) = 240000 m
2 hr * (3600 s / 1 hr) = 7200 s
v = d/t
v = 240000/7200
v = 33.33 m/s
Sprinter:
v = d/t
v = 100/9.5
v = 10.53 m/s
thus the car travels faster than sprinter by 33.33 - 10.53 = 22.8 m/s
Answer:
Resonance structures are represented in the picture below.
Explanation:
When there is a double pair of electrons shared between atoms in a molecule, the position of these electrons can be changed, without changing the molecule conformation. This occurs to stabilization, the electrons are relocated. These structures are called resonance structures.
In the molecule of NO₂F, nitrogen has 5 electrons in its valence shell, so it needs 3 electrons to be stable. Oxygen has 6 electrons and needs 2 to be stable, and fluor has 7 electrons and needs one electron to be stable.
Nitrogen still has electrons after the sharing, so it can also share one pair and will have a partial positive charge. One of the oxygens will not complete the octet, so will share only one pair f electron and will have a partial negative charge, that will compensate the positive charge in nitrogen.
The two resonance structures are shown below: