Answer:
(a) Dissolving sugar in water ⇒ physical change
(b) Crushing rock salt ⇒ physical change
(c) Burning sulfur ⇒ chemical change
(d) Digesting a chili dog ⇒ chemical change
Explanation:
<em>Physical changes</em> are those in which the substance does not alter its composition. They only involve changes of states of matter and the chemical substance is stil the same after the change occurs. By other hand, <em>chemical changes</em> are those in which new subtances are formed. So, the subtance is not the same after the change.
(a) Dissolving sugar in water ⇒ <em>physical change</em>; because we obtain a solution of sugar in water (sugar is stil sugar).
(b) Crushing rock salt ⇒ <em>physical change</em>; because we obtain crushed salt, but the chemical composition of the salt is not altered.
(c) Burning sulfur ⇒ <em>chemical change</em>; because sulfur is oxidized (chemical reaction) and new compounds are formed, for example sulfur dioxide.
(d) Digesting a chili dog ⇒ <em>chemical change</em>; because the digestion process is produced by the action of hydrocloric acid, and new compounds are formed.
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:
See explanation
Explanation:
Biology- digestion of food materials
Chemistry- dissolving salt in water
Astronomy - observing day and night
Physics - watching a television
Geography - observing weather changes during the day
Answer:
![\Huge \boxed{\mathrm{Kr}}](https://tex.z-dn.net/?f=%5CHuge%20%5Cboxed%7B%5Cmathrm%7BKr%7D%7D)
Explanation:
Krypton is an element in the periodic table with an atomic number of 36.
The symbol for Krypton is Kr.