Answer:
1. The energy intensity from the ruler going through the air
2. This one is pretty simple, you can add or take away things. This question is just asking you to list sounds from high pitch, to lowest pitch. Here are mine:
Timer
Microwave
Mouse clicking
Dog Barking
Voice
Typing
Knocking on door
Breathing
Foot Steps
Explanation:
<u>Given:</u>
Mass of pure iron (Fe) = 3.4 g
<u>To determine:</u>
Mass of HBr needed to dissolve the above iron
<u>Explanation:</u>
Reaction between HBr and Fe is
Fe + 2HBr → FeBr₂ + H₂
Based on the reaction stoichiometry-
1 mole of Fe reacts with 2 moles of HBr
# moles of Fe = mass of Fe/atomic mass of Fe = 3.4/56 g.mol⁻¹ = 0.0607 moles
Therefore # moles of HBr = 2*0.0607 = 0.1214 moles
Molar mass of HBr = 81 g/mole
Mass of HBr = 0.1214 moles * 81 g/mole = 9.83 g
Ans: Mass of HBR required is 9.83 g
Isotope - the same element, but different atomic mass so 1)35 Cl and 37 Cl
