Calculate the food energy (joules/g) of one of your food
samples. one chemistry calorie is equal to 4.186 joules. convert the energy you
calculated to kilojoules (1 kj = 1000 j). since nothing is given, an example is
avocadoes have 160 cal/100 g serving
(160 cal/ 100 g)(4.186 J/ 1 cal) (1 kJ/1000 J) = 0.0067 kJ/g
A substance that cant be broken down by cheamical or physical means is an Element.
Hope this helps
it's B Cell wall
please mark me as brainliest
<u>Answer:</u> The volume of bone for given sample is 
<u>Explanation:</u>
To calculate volume of a substance, we use the equation:

Density of bone =
(Conversion factor: 1 g = 1000 mg)
Mass of bone = 25 g
Putting values in above equation, we get:

Hence, the volume of bone for given sample is 
Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:


Firstly, find the total number of moles of magnesium metal:

Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:

According to stoichiometry, we form:

Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:

The total mass is given, so we have our second equation to solve:

We have two unknowns and two equations, we may then solve:


Express y from the first equation:

Substitute into the second equation:





Moles of nitride formed:

Convert this to mass:

Find the percentage:
