An element is a species of atom that has the same amounts of electrons and protons in their nuclei. To know which of these substances are elements, we can look it up in the periodic table of elements. The elements are as follows:
1.silicon
2.lead
3.silicone
5.iodine
Answer:
1.90 L
Explanation:
Using Boyle's law
Given ,
V₁ = 595 L
V₂ = ?
P₁ = 1.00 atm
P₂ = 55.0 atm
Using above equation as:

<u>The volume would be 1.90 L.</u>
Answer: -
15.55 M
35.325 molal
Explanation: -
Let the volume of the solution be 1000 mL.
Density of nitric acid = 1.42 g/ mL
Total Mass of nitric acid Solution = Volume of nitric acid x Density of nitric acid
= 1000 mL x 1.42 g/ mL
= 1420 g.
Percentage of HNO₃ = 69%
Amount of HNO₃ = 
= 979.8 g
Molar mass of HNO₃ = 1 x 1 + 14 x 1 + 16 x 3 = 63 g /mol
Number of moles of HNO₃ = 
= 15.55 mol
Molarity is defined as number of moles per 1000 mL
We had taken 1000 mL as volume and found it to contain 15.55 moles.
Molarity of HNO₃ = 15.55 M
Mass of water = Total mass of nitric acid solution - mass of nitric acid
= 1420 - 979.8
= 440.2 g
So we see that 440.2 g of water contains 15.55 moles of HNO₃
Molality is defined as number of moles of HNO₃ present per 1000 g of water.
Molality of HNO₃ = 
= 35.325 molal
It depends on the context iorn is a transition metal so it can hold a charge from 1-8