1. Bell Work Fill in the blanks. (Use your book to help you.) 1) Density is a __________ property that describes the relationship between ________ & ________ (see p189, last para) 2) Density is the amount of __________ in a given _________ or _________ (see p189, last para) 3) What is the mathematical formula used to determine density? (see page 191, top para) Date SPI 0807.9.7 Density If you do not have your textbook, go get it before the bell rings! physical mass volume matter volume space D= M V

2. Homework Instructions A) Write the definition of density (p546) B) Copy the 3 paragraphs at the top of p191 C) Do “Math Focus” 1 to 3 at the bottom of p191 D) Do number 7 on page 193 Note: Yes you can use a calculator for C and D Assigned Feb 6, 2015 SPI 0807.9.7 Density

3. Homework Task A) Write the definition of density (p546) Assigned Feb 6, 2015 SPI 0807.9.7 Density Answer Density is the ratio of the mass of a substance to the volume of the substance. F.Y.I.  Ratios are expressions that compare quantities, and they can be written as a fraction. D= M V Example:

4. Homework Task B) Copy the 3 paragraphs at the top of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Paragraph One Solving for Density To find and object’s density (D), first measure its mass (m) and volume (V). Then use the equation below MVMV D=

5. Homework Task B) Copy the 3 paragraphs at the top of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Paragraph Two Units for density consist of a mass unit divided by a a volume unit. Some units for density are g/cm 3, g/mL, kg/m 3, and kg/L. Remember that the volume of a solid is often given in cubic centimeters or cubic meters. So the density of a solid should be given in units of g/cm 3 or kg/m 3

6. Homework Task B) Copy the 3 paragraphs at the top of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Paragraph Three Using Density to Identify Substances Density is a useful physical property for identifying substances. Each substance has a density that differs from the densities of other substances. And the density of a substance is always the same at a given temperature and pressure.

7. Homework Instructions C) Do “Math Focus” 1 to 3 at the bottom of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Notes from p191: Math Focus The equation for density can also be rearranged to find mass and volume Mass = Density x Volume m = D x V Volume = density mass MDMD V= Volume = Mass divided by Density or

8. Homework Instructions C) Do “Math Focus” 1 to 3 at the bottom of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Math Focus: 1 st Problem Find the density of a substance that has a mass of 45 kg and a volume of 43 m 3 Density = volume mass Density = Mass divided by volume MVMV D= Density = 43 45 Density = 1.0465 rounded to 1.05 Density = 1.05 kg/m 3

9. Homework Instructions C) Do “Math Focus” 1 to 3 at the bottom of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Math Focus: 2 nd Problem Suppose you have lead ball whose mass is 454g. What is the ball’s volume? Note: Lead’s density is given in table 1 on p191 as 11.35 g/cm 3 Volume = density mass Volume = Mass divided by density mDmD V = Volume = 11.35 454 Volume = 40 cm 3

10. Homework Instructions C) Do “Math Focus” 1 to 3 at the bottom of p191 Assigned Feb 6, 2015 SPI 0807.9.7 Density Math Focus: 3 rd Problem What is the mass of a 15 mL sample of mercury? Note: Mercury’s density is in table 1 on p191 as 13.55 g/cm 3 Mass = 13.55 x 15 Mass = Density x Volume D x V m = Mass = 203.25 rounded to 203 Mass = 203 g

11. Homework Instructions D) Do number 7 from page 193 Assigned Feb 6, 2015 SPI 0807.9.7 Density Number 7, page 193 What is the density of an object that has a mass of 350g and a volume of 95 cm 3 ? Density = volume mass Density = Mass divided by volume MVMV D= Density = 95 350 Density = 3.6842 rounded to 3.68 Density = 3.68 g/cm 3