your answer is.....
D. have a large atomic radius
although they also increase going from left to right so if D is incorrect, B might be your answer. it depends on context of the lesson.
Answer:
2 in front of water and 1 in front of oxygen
Explanation:
This question is describing balancing a chemical reaction. A balanced chemical reaction has the same number of atoms of each elements on both the reactant and product side. According to the question, the reactants contains 4 atoms of oxygen. The reactants give rise to water (H20) and O2 in the products side.
This reaction is most likely the decomposition of hydrogen peroxide (H2O2) as follows:
H2O2 (l) ----> H2O (l) + O2(g)
Based on the description, H2O2 will be 2H2O2 as it is said to contain four atoms of oxygen. This means that, in order to have a balanced equation, we must place coefficient 2 in front of water and coefficient 1 in front of oxygen. That is;
2H2O2 (l) ----> 2H2O (l) + O2(g)
Answer:
Mass of the aluminium chunk = 278.51 g
Explanation:
For an isolated system as given the energy lost and gains in the system will be zero therefore sum of all transfer of energy will be zero,as the temperature will also remain same
A specific heat formula is given as
Energy Change = Mass of liquid x Specific Heat Capacity x Change in temperature
Q = m×c×ΔT
Heat gain by aluminium + heat lost by copper = 0 (1)
For Aluminium:
Q = 
Q = m x 17.94 joule
For Copper:

Q= 4996.53 Joule
from eq 1
m x 17.94 = 4996.53

Mass of the aluminium chunk = 278.51 g
Sure, if the mortality (death) rate is even higher than the birth rate.