integrated science a - unit 4: exam /
Key Questions with 100% Correct Answers.Quiz____?a beaker containing a chemical reaction feels hot to the touch.according to the law of conservation of energy, what best predicts the stability of the products? - Answer✓✓ if the reactants released thermal energy when they reacted, they must have lost an equal amount of potential energy. the products will be more stable.Quiz____?an atom of magnesium and two atoms of chlorine react and yield the compound of magnesium chloride. - Answer✓✓ Mg + 2Cl →→ MgCl2 Quiz____?based on this graph, what might be the best use of this radioactive isotope? - Answer✓✓ determine the age of objects less than 50,000 years old Page 1 of 9 1 / 2
Quiz____?element a has a half-life of 10 days. a scientist measures out 200 g of this substance. after 30 days pass, the scientist reexamines the sample.how much element a will remain in the sample? - Answer✓✓ 25 g Quiz____?examine the equation.2Ca + O2 →→ 2CaO what is the best classification for the equation's reaction? - Answer✓✓ synthesis Quiz____?examine the equation.
C3H8 + 5O2 →→ 3CO2 + 4H2O
what are the roles of the substances in the equation? - Answer✓✓ the substances C3H8 and 5O2 are reactants that react to form the products 3CO2 and 4H2O.Page 2 of 9
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