Show:
physical and chemical changes
fossils and biodiversity
chemical reactions
atoms
other 8th grade science
100
What type of change takes place when a paper is cut?
What is a physical change?
100
Where you find the oldest fossils
What is the bottom layer?
100
What is the left side of a chemical equation called?
What is a reactant?
100
What does the atomic number represent?
What are the number of protons?
100
What is the chemical makeup of Earth's atmosphere? 3 things, with percentages.
What is 78% nitrogen, 21 % oxygen, and 1% other gases?
200
What type of change occurs when iron rusts?
What is a chemical change?
200
variety of life
what is biodiversity?
200
What is the right side of a chemical equation called?
What is a product?
200
What is an atom that has a different number of neutrons from the original atom?
What is an isotope?
200
How can you make an electromagnet stronger?
What is add more wire coils? What is add more power?
300
A student applies a heat to a solid substance. Which indicates a chemical change? A. the substance becomes liquid but solidifies when cooled. B. the substance changes color and stays that color when cooled. C. the substance goes from liquid to gas quickly. D. The substance expands and stays the same color.
What is B?
300
chemical makeup of an organism is this type of adaptation.
What is physiological?
300
What is the name of the small number in a chemical equation?
What is a subscript?
300
How many electrons does hydrogen or helium like to have in order to be "happy"?
2
300
What is the pH range for a base?
What is 7.1-14?
400
True or False. Chemical changes create new elements.
False
400
What are differences among species, that can sometimes become an adaptation to help them survive?
What is variation?
400
The reaction shows potassium (k) reacting with oxygen (o) to form potassium oxide. (KO2) The mass of potassium is 39 grams and the mass of oxygen is 32 grams. How much potassium oxide is produced.
What is 71 grams?
400
compounds are made up of
2 or more elements chemically combined
400
Meerkats are small mammals that live in the desert. They forage for insects, lizards, bird eggs, and fruit over about a 3 mile territory. They watch the sky and let out a shrill cry when they see an owl or hawk, which are their predators. Which population will likely to survive in this environment? A. solitary meerkats B. meerkats that live in groups C. meerkats that forage at night D. meerkats that forage by day.
What is B?
500
Sara investigated the effects of hydrochloric acid on several solid substances. After placing one drop of HCL on a sample of CaCO3 bubbles form. Once bubbles stopped, a clear liquid and a white solid remained on the surface of the sample. What type of change occurred?
What is chemical change?
500
What tool helps you identify an unknow organism by distinguishing between the characteristics that describe the unknown?
dichotomous key
500
What coefficient is needed to balance the following equation: 4H2 + 2O2 ---> ____H2O
What is 4?
500
What is an atom that loses or gains an electron?
ions
500
What is an iron core wrapped in a coil of wire called?
What is a solenoid?