The structural formula for 2-methylpentane is in Figure 1. It shows all the C-C and C-H bonds explicitly.
The bond-line formula for 2-methylpentane is in Figure 2. We assume that a carbon atom is at the ends and junctions of the lines. We do not show the H atom, but we mentally assume that there are enough to give each carbon a valence of four.
A condensed structural formula is designed to be typed <em>all on one line</em>. We could write the condensed structural formula for 2-methylpentane as either (CH₃)₂CH-CH₂-CH₂-CH₃ or CH₃CH(CH₃)CH₂CH₂CH₃.
The horizontal C-C bonds are <em>optional </em>— you can include or omit them as desired.
Ne is the smallest
B is the biggest
It goes (smallest to largest) : Ne, F,C,B
You can see a physical change always but not always a chemical
Answer:

Explanation:
We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.
- ΔT= final temperature - initial temperature
The sample was heated <em>from </em> 58.8 degrees Celsius to 88.9 degrees Celsius.
- ΔT= 88.9 °C - 58.8 °C = 30.1 °C
Now we know three variables:
- Q= 4500.0 J
- c= 0.4494 J/g°C
- ΔT = 30.1 °C
Substitute these values into the formula.

Multiply on the right side of the equation. The units of degrees Celsius cancel.

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

The units of Joules cancel.


The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

The mass of the sample of metal is approximately <u>333 grams.</u>
It is going through a physical change