Answer:
The atomic theory has changed over time as new technologies have become available. Scientific knowledge builds on past research and experimentation. 400 B.C. Democritus, a philosopher in ancient Greece, began the search for a description of matter.
Explanation:
The mass of the photo frame : = 549.12 g
<h3>Further explanation</h3>
Given
a photo frame
two 5.2 mm sheets = 0.52 cm
22 cm by 20 cm dimension
Required
the mass
Solution
The volume of one sheet = l x w x h
= 22 cm x 20 cm x 0.52 cm
= 228.8 cm³
Mass of one sheet :
= density x volume
= 1.2 g/cm³ x 228.8 cm³
= 274.56 g
So for two sheets of polycarbonate :
= 2 x 274.56 g
= 549.12 g
Answer:
C-12 or C with a 12 superscripted on Upper left and 6 Subscripted on bottom left
Explanation:
Isotopic notation
