Week 12.1 & 2 Monday/Tuesday 11/30 - 12/01/20
19
Talling
1. Most elements that form a zigzag line in the
periodic table belong to which major group?
2. True or False- metalloids make up most of the
elements on the periodic table.
3. Would Co, and NaCl be considered an element
or compound? Explain.
os E 240 PM
11/30/20

1 metalloids

2 false

3 compound because it has more than one letter.

Explanation:

- lead + phosphoric acid = hydrogen + lead(ii) phosphate

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.