Answer:
A
Explanation:
They will collect samples from different sites and write their observations
The Mr is the mass numbers of each element added up so…. Fe = 56, O=16, H=1 … now add these up with the number of each element -> there’s 1 Fe, and 3 Os and 3 Hs as they are in brackets with a 3 outside-> (56+16+16+16+1+1+1=107) … your answer is 107
Answer:
2.52 x
J
Explanation:
The energy given off by the microwave can be determined by the application of Planck's energy formula:
E = hf
where: E is the required energy, h is Planck's constant (6.626 x 
Kg/s), and f is the frequency (3.8 x
Hz).
So that;
E = 6.626 x
x 3.8 x 
= 2.51788 x 
Therefore, the energy released by the wave is 2.52 x
J.
Because going down a column you are jumping up to the next higher main energy level (n) and each energy level is further out from the nucleus
Answer: A. To change the potential energy of the reactants.
Explanation:
Catalysts make such a breaking and rebuilding happen more efficiently. They do this by lowering the activation energy for the chemical reaction. Activation energy is the amount of energy needed to allow the chemical reaction to occur. The catalyst just changes the path to the new chemical partnership.