Answer: 1. Periods 2. One, electrons 3. Two, electrons 3. Elements 4. Electrons, outermost 5. One, two 6. Seven, six
Explanation: they needed one and two electrons to complete their outer shell, so the have same valence but negative.
Q=mc(change in temp)
Q is amount of heat, m is mass, c is specific heat
Water:
Q= (50.0g)(4.18 J/g°C)(63°C)
Q= 13167J
Aluminum:
Q= (200.0g)(0.900 J/g°C)(63°C)
Q= 11340J
Water requires more heat
Answer:
Greatly affected.
Explanation:
The stability of a nucleus is greatly affected by changing the number of nuclear particles because changing the number of nuclear particles i.e. neutron or proton will leads to change the element. When we change the number of protons in an atom, we will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive in nature so we can conclude that changing number of nuclear particles impact the stability of nucleus of an atom.
Answer: Formation of hydrogen iodide will occur.
Explanation:
When molecule of hydrogen gas 
and molecule of iodine gas 
collide with proper orientation and with sufficient amount of energy. This collision of the two different molecules of gases will result in the formation of hydrogen iodide.
The balanced chemical equation of the reaction will written as:
Answer:
2
Explanation:
In two reactions energy is released.
1) C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂ + heat
It is cellular respiration reaction.It involves the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.
Glucose + oxygen → carbon dioxide + water + 38ATP
2) 2H₂ + O₂ → 2H₂O ΔH = -486 kj/mol
The given reaction is formation of water. In this reaction oxygen and hydrogen react to form water and 486 kj/mol is also released.
The reaction in which heat is released is called exothermic reaction.
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
