Answer: E) In a closed system, the total energy always remains constant.
Explanation: For every system, the law of conservation of energy is applicable which states that the energy of the system remains conserved. Energy can neither be created nor destroyed.
A closed system is one which can exchange energy with the surroundings but not mass. Thus if a system absorbs energy, the equivalent amount of energy is lost by surroundings, thus the total energy remains constant.
If a system loses energy, an equivalent amount of energy is gained by surroundings, thus the total energy remains constant.
Answer:
Alien Species
Explanation:
This is known as an alien species threat to biodiversity as there is a newly added species taking over another. Mongooses were intended to control the snake population but it got out of control and is now threatening snake life in Hawaii.
Change in the amount of volume left inside the basketball for the remaining air coming in
Answer:
B. Hydrogen and oxygen molecules
General Formulas and Concepts:
<u>Chemistry - Reactions</u>
- Reactants are always on the left side of the arrow
- Products are always on the right side of the arrow
Explanation:
<u>Step 1: Define</u>
Reaction RxN: 2H₂ + O₂ → 2H₂O
<u>Step 2: Identify</u>
Reactants: H₂ and O₂
Products: H₂O
Answer:
C. I, III , IV
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
