all the elements in group 18 are Nobel gases or inert gases . all the elements such as neon , helium, argon etc. ,their outermost shell is completely filled . The noble gases have the largest ionization energies, reflecting their chemical inertness
<span> Au</span>₂(SeO₄)₃
O = -2 × 4 = -8
Se = + 6
So,
(+6 - 8) = -2
Means (SeO₄) contains -2 charge, Now multiply -2 by 3
-2 ₓ 3 = -6
Means,
Au₂ + (-6) = 0
Au₂ = +6
Or,
Au = 6 / 2
Au = +3
Result:
Au = +3
Se = +6
O = -2
Ni(CN)₂
Cyanide (CN⁻) contains -1 charge,
So,
N = -3
C = +2
Then,
Ni + (-1)₂ = 0
Ni - 2 = 0
Or,
Ni = +2
Result:
N = -3
C = +2
Ni = +2
The first statement (Matter is neither created nor destroyed) is correct.
The second statement would violate the law of conservation of mass (I will refer to this as LCM), as it would mean matter can "flow" into the universe, but not out, meaning the total matter will never be less than it was before.
The third statement violates LCM because it means matter is created during a reaction, which is not true.
The last statement violates LCM because it means matter is lost during a reaction, which is not true.
Answer:
d making models.
Explanation:
When scientists create a representation of a complex process, they are inferring that they are making models.
A model is an abstraction of the real world or a complex process. Models are very useful in developing solutions to processes that are not easily simplified.
- The models allow a part of a body to be simply studied.
- Through this simple abstraction, extrapolations to other parts of the system can be deduced.
- This can give very useful insights into the other parts of the system.
- The heterogeneity of complex processes is a huge limitation to understanding them.
- A homogenous part can be modelled and used to understand the system.
