The mass of a watch glass was measured four times. the masses were
99.997 g, 100.008 g, 100.011 g, and 100.005 g. what is the average
mass of the watch glass?

The average mass of the watch glass is 100.005g.

Given that,

Now the average mass of the watch glass should be

= 100.005 g

Therefore we can conclude that the average mass of the watch glass is 100.005g.

Learn more about the mass here: link

Explanation:

1. Sum of Measurements

2. Average mass

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).