Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
Answer:
No, because she is hoping that people will vote for her.
Explanation:
Altruism is when you do something for others and have very little expectation of getting something in return. In this case, Janetta expected something in return from her friends. We may not also be sure of the sincerity of Janetta appreciating friendship. From the above definition of altruism, we conclude that Janetta's actions are not altruistic because she hoped that people will vote for her.
Answer:
8.467 gm
Explanation:
The law governing this problem is "The Law of Constant Composition "
As per this law, all compounds irrespective of their origin and source have the same composition and properties in their purest form
It is a simple proportion and ratio related problem.
1.50 grams of carbon require 2.0 grams of oxygen
1.0 grams of carbon will require oxygen
=
6.35 grams of carbon will require oxygen
= 8.4666\\= 8.467
It would take 30 minutes
You would do 15.0 divided by 0.5