Answer: hydrogen
Explanation: hydrogen gas is a major component of water which occupies a large portion of the Earth's atmosphere
mass (m) = ? , volume = 18.0 ml , density = 1.42 g/ml .

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Answer:
Newton's Cradle is a neat way to demonstrate the principle of the CONSERVATION OF MOMENTUM.
What happens here is when the ball on one end of the cradle is swung and it hits the other balls that are motionless, or stationary, the momentum of the swinging ball is transferred to the next ball upon impact.
Momentum is not lost in this action, what happens when it hits the next ball, the momentum is transferred to the next one, and then the next, and the the next, till it reaches the last ball on the other end. Since nothing is next to the last ball, it pushes the ball upwards, which will swing down and repeat the process going the other way.
This also demonstrates the CONSERVATION OF ENERGY. As you will see, the energy continues to move through the other balls, passing it from one ball to the other, which keeps this constantly moving.
If people have children, If people die, and if there is a fire or volcanic eruption.
Answer:
H2S(g) + 2OH^-(aq) --------> S^2-(aq) + 2H2O(l)
Explanation:
We know that the net ionic equation shows the major reaction that occurs in the reaction system.
The molecular reaction equation is;
H2S(g) + 2NaOH(aq) ------> Na2S(aq) + 2H2O(l)
The complete ionic equation is;
H2S(g) + 2Na^+(aq) + 2OH^-(aq) --------> 2Na^+(aq) + S^2-(aq) + 2H2O(l)
Net ionic equation;
H2S(g) + 2OH^-(aq) --------> S^2-(aq) + 2H2O(l)