Use the chemical equation to complete the activity.
2Cu+S→Cu2S
Copper (Cu) reacts with sulfur (S) to form copper sulfide as shown in the equation. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction. In this reaction, all of the copper and all of the sulfur react. Before running the experiment, the scientist expected the products of the reaction will be a total of 15.9 grams of copper sulfide (Cu2S). In 1–2 sentences, explain the law that the scientist used to predict that the product of the reaction would be 15.9 grams of copper sulfide.
The scientist used the law of conservation of mass to predict that the product of the reaction would be 15.9 grams of copper sulfide. According to this law, matter cannot be created or destroyed, so the total mass of the reactants must be equal to the total mass of the products.
Where did the first civilization of India arise?
(1 point)
Responses
along the Ganges River
along the Ganges River
along the Indus and Sarasvati Rivers
along the Indus and Sarasvati Rivers
near the coast of the subcontinent
near the coast of the subcontinent
on the central plateau
along the Indus and Sarasvati Rivers
What did the Indus Valley civilizations use their granaries for?
(1 point)
Responses
defense bulwarks
defense bulwarks
government offices
government offices
storing food
storing food
housing travelers
storing food
How did Chandragupta Maurya react to his fear of his enemies?
(1 point)
Responses
set up large network of spies
set up large network of spies
reached out to enemies with peace proposals
reached out to enemies with peace proposals
aggressively attacked most neighboring kingdoms
aggressively attacked most neighboring kingdoms
isolated India from all communication from outside
set up large network of spies
Why did multiplication and division become easier during the Gupta empire?
(1 point)
Responses
They were the first to use base-10 numbers.
They were the first to use base-10 numbers.
They were the first to understand long division.
They were the first to understand long division.
They created a numeral for zero.
They created a numeral for zero.
They combined Chinese and Greek knowledge.