Answer:
a ruler or measuring cups are ways of measuring
Explanation:
Heres the best help i can give you There is a couple different ways to determine if a bond is ionic or covalent. By definition, an ionic bond is between a metal and a nonmetal, and a covalent bond is between 2 nonmetals. So you usually just look at the periodic table and determine whether your compound is made of a metal/nonmetal or is just 2 nonmetals
Which of these measurements is expressed as three significant figures?
C. 4.20 g
Missing question: Z:X = 7:1 A:Z = 2.5:1 A:Z = 2.2:1 Y:X = 11:1.
Answer is:<span> Z:X = 7:1 and Y:X = 11:1.
Law of multiple proportions or Dalton's Law
said that the ratios of the masses of the second element which
combine with a fixed mass of the first element will be ratios of small whole
numbers.
In this example ratios are whole numbers, A:Z = 2.5 : 1
and A:Z = 2.2 : 1 are not whole number ratios.</span>
The density is 3.144 g / cm^3.
<u>Explanation</u>:
If effective number of atom in NaCl type structure, z = 4
a = 705.2 pm ⇒ In centimeter = 705.2 
10^-10
Na = 6.023 10^23
density = (molecular weight) (z) / (Na) (a^3)
where molecular weight of KI is 166 g,
Z represents the atomic number
density = (molecular weight) (z) / (Na) (a^3)
= (166 4) / (6.023 10^23) (705.2 10^-10)
density = 3.144 g / cm^3.
