Answer:
A, and B.
Explanation:
A and B are the ones that are physical. The others are social and economic.
Market economies are based on market forces like supply and demand. Mixed economies fall in the middle of market and command economies (where economic choices are governed by some central entity usually the government). The former Soviet Union (USSR) is an example of a command economy where economic choices (what to buy, sell and produce) where made by the government. If Australia is becoming more of a market economy and less of a mixed economy, fewer decisions are made by the government. Here's a diagram of two major types of economies:
Command Economy <-------------- Mixed Economy --------> Market Economy
(Government makes the decisions) (A little of both) (Individuals decide)
Answer:
The hydrogen gas is prepared in the laboratory required zink granules, dilute sulphuric acid or dilute hydrogen chloride, flask or woulfe’s bottle, and thistle funnel. by the downward displacement of water because it is a gas lighter than water
Reaction:
Zn (s)+2HCl (aq) →ZnCl2(aq)+H2(g)
Zn (s)+H2SO4(aq)→ZnSO4(aq)+H2(g)
The zinc granules are taken in a flask or Woulfe’s bottle and It is connected with the delivery tube to a water trough containing water. Dilute sulphuric acid is poured slowly from the thistle funnel. The hydrogen gas is released and collected in a gas jar by by the downward displacement of water as H2 gas lighter than water
