Question

1. the table below shows

a scientist has a sample of metal that could be either cobalt or nickel. which of the following properties could be tested to classify the metal shape?
a. mass
b. density
c. electrical conductivity
d. reactivity with oxygen

1. water is sometimes called the universal solvent because it is a polar molecule that dissolves many substances. which of the following is soluble in water?

a. ice
b. metals
c. oil
d. salts

1. gabriel is testing the properties of four brands of golf balls. he places them in graduated cylinders containing 100 milliliters (ml) of water and determines that each ball has a volume of 20 cubic centimeters (cm³). he places the balls on a balance and finds that each has a different mass measured in grams (g). the properties of the golf balls are shown in the chart below.

golf ball properties

ball	mass (g)	volume (cm³)
b	18	20
c	30	20
d	33	20

gabriel uses these numbers to find the density of the golf balls using this formula: density = mass/volume. water has a density of 1.0 g/cm³. which ball will float?
a. ball a
b. ball b
c. ball c
d. ball d

Explanation:

Step1: Analyze question 4

Mass is an extensive property and can vary depending on the amount of the sample, so it cannot be used to classify the metal. Electrical conductivity and reactivity with oxygen are the same for both cobalt and nickel according to the table. Density is a characteristic intensive property and can be used to identify the metal as the densities of cobalt and nickel are different.

Step2: Analyze question 5

Ice is solid - phase water and not a solute in water. Metals are insoluble in water. Oil is non - polar and insoluble in polar water. Salts are ionic compounds and are generally soluble in water due to the interaction between the ions and the polar water molecules.

Step3: Analyze question 6

Use the density formula $\text{density}=\frac{\text{mass}}{\text{volume}}$. For ball A, $\text{density}_A=\frac{22}{20}=1.1\ g/cm^{3}$. For ball B, $\text{density}_B = \frac{18}{20}=0.9\ g/cm^{3}$. For ball C, $\text{density}_C=\frac{30}{20}=1.5\ g/cm^{3}$. For ball D, $\text{density}_D=\frac{33}{20}=1.65\ g/cm^{3}$. A substance will float in water if its density is less than the density of water ($1.0\ g/cm^{3}$), so ball B will float.

Answer:

1. b. Density
2. d. Salts
3. b. Ball B