Metals, Nonmetals, & Metalloids
All of the following are properties used to classify elements as metals, non-metals, and metalloids EXCEPT —
texture
conductivity
luster
malleability
texture
In science class today, students participated in a lab in which they created a “marshmallow man”. Students had to perform tests on their “marshmallow man” and determine whether they had caused a chemical change or a physical change to occur. Describe 2 pieces of evidence that would support the idea that there has been a chemical change.
Describe 2 pieces of evidence that would support the idea that there has been a chemical change.
- The marshmallow turning into ash, color change, smoking marshmallow, smell of burning marshmallow
After reading the liquid level in a graduated cylinder, what must a student determine in order to calculate the density of the liquid?
mass
A student is examining an object in science class. It is a pale yellow, brittle solid, with no shine.
The sample is most likely a —
A student mixes a solid with a liquid in a beaker. Which of the following describes a chemical change?
a. The liquid begins to heat up and a gas is formed.
b. The solid dissolves into the liquid.
c. The solid falls to the bottom of the beaker.
d. Nothing happens.
a. The liquid begins to heat up and a gas is formed.
A balance and a graduated cylinder are used to determine the density of a mineral sample. The sample has a mass of 14.7 g and a volume of 2.2 cm3. What is the density of the mineral sample?
6.7g/cm3
A student is examining an object in science class. It is solid, does not conduct, malleable but not ductile, and is a shiny silver color.
The sample is most likely a —
Metalloid
You dissolve a powder in water, and then bring it to a boil so that it begins to steam. You then add some food coloring so that the substance turns green. Is this an example of a physical or a chemical change and WHY?
physical change, phase changes, adding color, dissolving, and temperature changes are all examples of physical changes.
A student measured the mass and volume of a metal sample using a triple beam balance and a graduated cylinder. The sample has a mass of 16.7 grams and a volume of 4.4 cm3.
What is the density of the metal sample rounded to the nearest tenth?
Record your answer. Be sure to use the correct place value.
3.8g/cm3
A company is designing a new cell phone. They need a solid material that conducts electricity and can be made into a thin wire.
Which material would best fit their needs?
Metal
Students combine several chemicals and record the observations in their science notebooks. A list of the observed results is given here. • Production of a gas (bubbles) • Phase change (solid to liquid) • A precipitate forms • Change in shape • Crystals dissolving • Heat produced How many of the observations are evidence that a new substance was formed?
3
A student measures the mass and volume of a small cube made of an unknown metal. The mass of the cube is 25.0 g, and the volume of the cube is 3.19 cm3. The student is told that the cube is a sample of one of the four metals listed in the table.
Gold: 19.30g/cm3
Iron: 7.85g/cm3
Silver: 10.50g/cm3
Tin: 7.28g/cm3
Iron
Copper is a common metal. Describe the luster, conductivity, and malleability you would expect.
Luster - shiny, conductivity - conductive, malleability - malleable
Which characteristic is shared by all chemical reactions?
The formation of a new substance
The mass of an unidentified rock is 13.2 grams. Students determine the volume of the rock by placing the rock in a cylinder with water. Before they place the rock in the graduated cylinder, the water level is 30mL. After the rock is placed in the graduated cylinder, the water level rises to 37.4mL. The students calculate the density of the rock. They determine the identity of the rock based on the density ranges in the table.
Coal:1.1-1.9
Dolomite: 2.8-2.9
Peridotite: 3.1-3.4
Sandstone: 2.2-2.7
Density = 1.78g/mL, so the rock must be coal.