Answer:
The tension in string P is 25 N, while that of Q is 85 N.
Explanation:
Considering the conditions for equilibrium,
i. Total upward force = Total downward force
+ = 110 N
ii. Taking moment about P,
clockwise moment = anticlockwise moment
110 × (2.5 - 0.8) = × (3 - 0.8)
110 × 1.7 = × 2.2
187 = 2.2
=
= 85 N
From the first condition,
+ = 110 N
+ 85 N = 110 N
= 110 - 85
25 N
Therefore, the tension in string P is 25 N while that of Q is 85 N.
Sodium sulfide formula is Na₂S.
Na is a group 1 element, it has one valence electron therefore it is ready to give that valence electron and form an ionic bond. Once it gives out the electron it becomes a positive ion - Na⁺
sulfur is a group 6 element, has 6 electrons its outer shell and needs to gain 2 more electrons to become stable. Once it gains 2 electrons it becomes a negative ion - S²⁻.
Since Na only gives out 1 electron, S²⁻ ion needs to take in 2 electrons, therefore forms an ionic compound with 2 Na⁺ ions.
decomposition of Na₂S is as follows;
Na₂S(s) --> 2Na⁺(aq) + S²⁻ (aq)
Answer:
They can give us information and energy.
Explanation:
Fossils can be burned to give us energy and fuel. They can also give us information about the earths history.