Answer:
D. The mixing of warm and cold water
Explanation:
The density of the wood : 1.45 g/cm³
<h3>Further explanation </h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:

ρ = density
m = mass
v = volume


Answer:
= C3H4N
Explanation:
We are given; 90 grams carbon, 11 grams hydrogen, and 35 grams nitrogen.
We first calculate the number of moles of each element.
Carbon = 90g/12 g/mol
= 7.5 moles
Hydrogen = 11 g/ 1 g/mol
= 11 moles
Nitrogen = 35 g/ 14 g/mol
= 2.5 moles
The we get the mole ratio of the elements;
= 7.5/2.5 : 11/2.5 : 2.5 /2.5
= 3 : 4.4 : 1
= 3 : 4 : 1
Therefore;
The empirical formula will be; C3H4N