Answer:
Choice A.
A low birth to death ratio
Explanation:
A low birth to death ratio means that people are dying faster than they are being born. This leads to a decreasing population size.
Answer:
Hydrogen H₂ will be the limiting reagent.
The excess reactant that will be left after the reaction is 3.45 moles.
4.3 moles of water can be produced.
Explanation:
The balanced reation is:
2 H₂ + O₂ → 2 H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- H₂: 2 moles
- O₂: 1 mole
- H₂O: 2 moles
To determine the limiting reagent, you can use a simple rule of three as follows: if by stoichiometry 1 mole of O₂ reacts with 2 moles of H₂, how much moles of H₂ will be needed if 5.6 moles of O₂ react?

moles of H₂= 11.2 moles
But 11.2 moles of H₂ are not available, 4.3 moles are available. Since you have less moles than you need to react with 5.6 moles of O₂, <u><em>hydrogen H₂ will be the limiting reagent</em></u> and oxygen O₂ will be the excess reagent.
Then you can apply the following rules of three:
- If by reaction stoichiometry 2 moles of H₂ react with 1 mole of O₂, 4.3 moles of H₂ will react with how many moles of O₂?

moles of O₂= 2.15 moles
The excess reactant that will be left after the reaction can be calculated as:
5.6 moles - 2.15 moles= 3.45 moles
<u><em>The excess reactant that will be left after the reaction is 3.45 moles.</em></u>
- If by reaction stoichiometry 2 moles of H₂ produce 2 moles of H₂O, 4.3 moles of H₂ produce how many moles of H₂O?

moles of H₂O= 4.3 moles
<u><em>4.3 moles of water can be produced.</em></u>
Answer:
B.0.2 J/g°C
Explanation:
From the attached picture;
- Heat attained in the solid phase is 200 Joules
- Change in temperature is 50°C ( from 0°C to 50°C)
- Mass of the solid is 20 g
We are required to determine the specific heat capacity of the substance;
- We need to know that Quantity of heat is given by the product of mass,specific heat capacity and change in temperature.
- That is; Q = mcΔT
Rearranging the formula;
c = Q ÷ mΔT
Therefore;
Specific heat = 200 J ÷ (20 g × 50°c)
= 0.2 J/g°C
Thus, the specific heat of the solid is 0.2 J/g°C
Atomic number = No. of proton = 1
so, your answer is 1
Questions:
1) Kinetic energy is the energy an object has due to its ________.
2) Kinetic energy can be calculated from what two measurements?
3) What is the standard unit of measurement for kinetic energy?
4) What would happen to the kinetic energy of an object if you doubled the mass?
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Answers:
1) Motion
2) Velocity and mass
3) Joule
4) The kinetic energy would double