The answer is 1s2 2s2 2p6
Answer:
1460 red Lego bricks will be sufficient for 10 kg child to consume to reach the LD-50 threshold.
Explanation:
Average mass of a Lego brick = 2.50 grams
Amount of cadmium in 1 gram of red lego brick = 274 μg =
1 μg =
Amount of cadmium in 2.50 grams of lego brick :
LD-50 for cadmium = 100 mg/kg
For a 10.0 kg child the amount of cadmium that will be lethal :
1 g = 1000 mg
Let the number of red Lego bricks ingested by the child to reach the LD-50 threshold be x.
x × (Amount of Cd in single 2.50 g red lego brick) = 1g
1460 red Lego bricks will be sufficient for 10 kg child to consume to reach the LD-50 threshold.
Answer and Explanation:
- In spontaneous reactions, activation energy (Ea) of the forward reaction is less than that for the same reaction running in the reverse direction.
- Firstly, The activation energy <em>is the minimum energy requirement for the reacting molecules to initiate the reaction.</em> <em>It is the potential energy difference between the activated complex and the reactants on the energy profile diagram.</em>
- Spontaneous reactions are mainly exothermic reactions and are represented on the energy profile diagram as shown in <em>the attached image.</em>
- <u><em>The forward reaction looks like: </em></u>Reactants (A) → products (B) + heat
As the spontaneous reaction (exothermic), the energy of the products is lower than that of the reactants.
The difference in energy between reactants and products is the enthalpy change of the reaction (ΔH).
The activation energy (Ea) of the forward direction is the difference between the energy of the the activated complex state and the reactants state.
- <u><em>In the case of the reverse direction:</em></u> B + heat → A
In the reverse direction we need a supply of energy because the reaction is converting from a more stable state (low energy) to a lower stable state (high energy).
The supply in the reverse direction is ΔH, the amount of heat released in the forward direction.
Here, the activation energy of the reverse direction will be <em>(Ea of the forward direction + ΔH)</em>.
The difference between the Ea of the reverse and forward direction is ΔH.
Ea reverse = Ea forward + ΔH.
<em>So, in spontaneous reactions, the value of the Ea of forward direction is lower than the same reaction running in the reverse direction.</em>
Answer: 43.125g
Explanation:4Na+ O2=2Na2O
Molar mass: 23. 32. 62. React.mass: 92.
About a month
because it takes the moon 29.5 days to completely cycle through all eight phases