Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
Answer: Option (b) is the correct answer.
Explanation:
It is known that metals are the species which readily lose an electron and tend to attain a positive charge.
For example, atomic number of sodium is 11 and its is an alkali metal. It electronic distribution is 2, 8, 1.
And, in order to attain stability it readily loses an electron and thus it become 
ion.
Also, it is known that species which tend to transfer or donate their valence electrons to other atoms tend to form ionic bond and the compound formed is known as ionic compound.
Therefore, we can conclude that the statement metal atoms held together by ionic bonds best describes a metal solid.
Answer:
oceans is the answer that I got
<span>C. older material is located below younger material
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Answer: Option (A) is the correct answer.
Explanation:
Elements present in group 1 are known as alkali metals. Whereas elements present in group 2 are called alkaline earth metals and elements from group 11 to 12 are transition metals.
As it is known that metals have the ability to lose electrons in order to attain stability and electricity is the flow of electrons from one point to another.
Therefore, metals are good conductors of heat and electricity.
Thus, we can conclude that the statement it’s between groups 1 to 12 because it is metal best explains the probable position of the substance in the periodic table.
