Answer:
electrons
Explanation:
The photoelectric effect occurs when electrons are emitted from metal when the metal is struck by light of certain frequencies.
Some of the applications of this effect include photomultipliers (which are a key component in spectroscopy instruments) and night vision devices.
Answer:
B. 4 Fe + 3 0₂---> 2 Fe₂O3
Explanation:
(A) Ir + O₂--> IrO₂ No: Ir is iridium
(B) 4 Fe + 3 0₂---> 2 Fe₂O3 Yes: Fe is iron and O is oxygen, and the equation is balanced.
(C) I+ 0₂ ---> 10₂ No: I is iodine
(D) 3 Ir + 0₂ -> 6 Ir₂03 No: I is iodine
In an exothermic reaction, heat is released. ΔH for an exothermic reaction is negative. That means that the energy stored in the reactants is higher than the energy stored in the products.
The opposite is true for an endothermic reaction. Heat is absorbed, and <span>ΔH for an endothermic reaction is positive. This means that energy stored in the products is higher than the energy stored in the reactants.</span>
