Answer: 
: Pure substance, Element
: Pure substance , Element
: Pure substance, Compound
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: 
and
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example:
Heterogeneous Mixture : Mixture that has its different components mixed unevenly within the substance
. Example: Air
Homogeneous Mixture : Mixture that has its different components mixed evenly within the substance. Example: sugar dissolved in water
Each of the following is a characteristic of acids except D. Solid.
Answer:
To calculate the average atomic mass, multiply the fraction by the mass number for each isotope, then add them together.
Answer:
Magnesium hydroxide, Mg(OH)2, is an Arrhenius base and therefore also a Brønsted-Lowry base.
However, water can also act as a base by accepting a proton from an acid to become its conjugate base, H3O+. where Al(OH)3 is acting as a Lewis Base.
Explanation:
Arrhenius acids and bases
An Arrhenius acid is any species that increases the concentration of H+start text, H, end text, start superscript, plus, end superscript in aqueous solution.
An Arrhenius base is any species that increases the concentration of OH−start text, O, H, end text, start superscript, minus, end superscript in aqueous solution.
Answer:
The Retention factor (rf) value is = 0.2
Explanation:
- Retention factor (Rf) is factor used substances that could be separated using Chromatography. Retention factor determines how fast the component can move on the chromatogram (stationary phase) after elution. Elution occurs when mobile phase (solvent) moves across the stationary phase when the solute has been spotted on the origin.
- Retention factor (Rf) ranges from value between 0 and 1. The closer the value to 1, the faster it can move upon elution. Rf can be calculated.
- Rf value = distance moved by the solute / distance moved by the solvent
= 0.40cm / 2.00cm
= 0.2
