properties of matter
color, shape, luster, texture, melting temperature, state of matter, mass, volume, density
physical properties
Is sugar dissolved in water a pure substance or mixture? Why?
mixture: Even thought you cannot see the sugar it is still there, just smaller. If you use evaporation, boiling, or crystallization, you can separate the water from the sugar.
Is a mixture (trail mix, brass of copper and zinc, and concrete) a physical or chemical change? Why?
flammability, reactivity, acidity, oxidation
chemical properties
carbon dioxide (CO2), water (H2O), gold (Au), hydrogen (H) are examples of what types of pure substances?
elements and compounds
list signs of physical changes
change in shape, change in size, change in form/state of matter, same substance, can be reversed
Describe the arrangement of the atoms in a cube made of solid gold vs. a cube that is made of styrofoam.
The atoms are heavier and more compact in a cube of gold vs. a cube of styrofoam.
is air a pure substance or a mixture? why?
mixture of many different gases, water, dust, pollen, etc.
list signs of a chemical change
flame/light, gas/bubbles, temperature change, color change, new substance forms, odor/smell, cannot be reversed
Where did matter on Earth come from?
stars, supernovas
What is the difference between homogeneous and heterogeneous mixtures?
Homogeneous looks the same throughout and you can't take the mixture apart. Heterogeneous can be taken apart and is very easy to tell the parts of the mixture.
physical or chemical? An ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone. LIST EVIDENCE
physical - changes in state of matter
A solid metal that is 137g and has a volume of 15 cm3. What is the density of the metal?
9.13 g/cm3 or 9 g/cm3
Describe a separation technique for a real-life mixture scenario
answers may vary (wastewater, desalination, separating ore in Earth's crust, mining minerals for medicine)
physical or chemical? Grass grows using sunlight and air. LIST THE EVIDENCE
chemical - photosynthesis uses water, carbon dioxide, and the sun to make sugar for the plant to grow