The density of pure gold (au) is 19.3 g/cm3. what is the mass of a block of gold that measures 1.2 cm x 5.00 cm x 3.20 cm? please show work.
Given: Density of pure gold = 19.3 g /cm^3
Measurement of block of gold =1.2 cm x 5.00 cm x 3.20 cm
To calculate : mass of gold
Formula used: Density = Mass / Volume
Volume = 1.2 cm x 5.00 cm x 3.20 cm = 19.2 cm^3
Mass of gold = Density X volume = 19.3 g /cm^3 X 19.2 cm^3 = 370.56 g
Answer:
electrons fill lower energy levels first before occupying higher energy levels.
Explanation:
The Aufbau's principle describes that electrons fill lower energy levels first before occupying higher energy levels.
In writing the electronic configuration of atoms, the Aufbau's principle is one of the most important principles to consider.
It states that "sublevels with with lower energies are filled up before those with higher energies".
Sublevels do not fill up in numerical order.
Chromium (Cr) is round in d block
The smallest particle of an element that still retains the chemical properties of it is an atom.
Answer:
15.438g H2O
Explanation:
First you need to find the reaction equation:
2H2O+2Na=2NaOH + H2
Hydrogen is a diatomic molecule so it will have a subscript of 2 on the right hand side. From there we can balance the reaction.
Then we can use stoichiometry:
34.2g NaOH * (1 mol NaOH/39.908g NaOH) * (2 mol H2O/2 mol NaOH) * (18.015g H2O/1 mol H20) = 15.438g H2O
It is important that when you use stoichiometry that all your units cancel out until you only have the unit you want.