Answer:
The answer to your question is below
Explanation:
11. Alkali metals
12. Halogens
13. Transition metals
14. Halogens
15. Noble gases
16. Alkaline earth metals
17. Transition metals
18. Alkaline earth metals
19. Transition metals
20. Alkali metals
21.- Periods
22.- Calcium
23.- Iodine, I
24.- A. atomic number
Explanation:
Distinguish chemical substances from mixtures
Key Points
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.
A chemical substance is composed of one type of atom or molecule.
A mixture is composed of different types of atoms or molecules that are not chemically bonded.
A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.
A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.
Various separation techniques exist in order to separate matter, including include distillation, filtration, evaporation and chromatography. Matter can be in the same phase or in two different phases for this separation to take place.
Terms
substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.
elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.
mixtureSomething that consists of diverse, non-bonded elements or molecules.
Answer:
Relative motion of source and observer.
Explanation:
Doppler Effect : It is the change in the observed frequency of the wave due to<em><u> relative motion of the source and object </u></em>.
B. a nucleus with a positive charge.
Answer:
Force of attraction = 35.96
N
Explanation:
Given: charge on anion = -2
Charge on cation = +2
Distance = 1 nm =
m
To calculate: Force of attraction.
Solution: The force of attraction is calculated by using equation,
---(1)
where, q represents the charge and the subscripts 1 and 2 represents cation and anion.
k = 
F = force of attraction
r = distance between ions.
Substituting all the values in the equation (1) the equation becomes

Force of attraction = 35.96
N