November 13, 2019

 Which electron configuration represents the electrons in an atom of sulfur in an excited state?

(1) 2 – 8 – 6

(2) 2 – 7 – 7

(3) 2–8– 7

 (4) 2–7– 8

Answer : 2) 2-7-7

Explanation: We must first look at the Periodic Table at the Reference Table, and find Sulfur. Sulfur's electron configuration is 2-8-6 according to the Reference Table. An excited state is a state in which an electron jumps to a higher energy level, while the g...

September 27, 2019

Which compound is an electrolyte?

(1) CH3CHO

(2) CH3OCH3


(4) CH3CH2CH3

Answer: Choice 3 CH3COOH is the correct answer choice


Electrolytes are compounds that can conduct electricity.

Electrolytes are: 

Ionic compounds melted or dissolved in water (ionic means metal +nonmetal, metal +polyatomic ion, or two polyatomic ions together).

Acids (The list of acids is on the Regent Reference table) 

Bases (The list...

September 14, 2019

There is a simple and easy way to identify ionic  versus compounds.

Ionic compounds can be of three types:

1. Metal + Nonmetal

To figure out whether an element is a metal or a nonmetal, look at the periodic table. Elements on the right of the staircase on the periodic table are metals. Elements to the left of the staircase on the periodic table are nonmetals. Hydrogen is a nonmetal even though it is located on the rig...

September 12, 2019

August 2019 Chemistry Regent Exam

Write the general formula for the homologous series to which propene belongs.

Answer: This questions mentions homologous series, which are groups of organic compounds. We can look at the Regent Reference Table Q, that is titled "Homologous Series of Hydrocarbons" to figure out the answer to this question. Propene is an organic molecule that has an ending "ene", which means its belongs to...

August 30, 2019

A 0.050 M aqueous solution of which compound is the best conductor of electric current?

(1) C3H7OH

(2) C6H12O6 

(3) MgSO4

(4) K2SO4

Answer and Explanation:

First we need to go over what kind of compounds are the best conductors of electricity, or electrolytes.

These are: metals, ionic compounds that are molten, ionic compounds that are dissolved in water, strong acids and strong bases.  Let's now go over the compounds listed...

July 24, 2019

Reference table on Chemistry regent is your very best friend. It has the answer to probably around 80% of the questions asked. Today, we will go over understanding how to use table G and what kind of information it contains. 

Table G is titled as Solubility Curves at Standard Pressure. The x-axis title is Temperature and the y-axis is Solubility (g solute/100. g H2O). This chart shows us how much of each substance dissol...

June 17, 2019

Chemistry regent in approaching. This year, it will be administered on June 25, 2019 at 9 am.

Format: The test consists of fifty multiple choice questions and thirty-five short response questions.

Score conversion: There is a score conversion for every Chemistry Regent administered. For example for June 2012 test, a student got got 1 answer wrong would get 98, 10 answers wrong would be 86, and 36 answers wrong would pas...

May 13, 2019

All students in public schools in New York state are required to take Regents. Chemistry regent is a three hour test that consists of  85 questions, 50 of which are multiple choice and the rest are short responses. Chemistry regent covers the topics of: Atomic Concepts, Periodic Table, Moles/Stoichiometry, Chemical Bonding, Physical Behavior of Matter, Kinetics/Equilibrium, Organic Chemistry, Oxidation-Reduction, Acids,...

July 12, 2018

Which statement describes a chemical property of iron? (1) Iron oxidizes. (2) Iron is a solid at STP. (3) Iron melts. (4) Iron is attracted to a magnet. Answer and Explanation: Let's first begin by defining a chemical property. Chemical property is a characteristic observed during a chemical reaction (during a reaction the identity of the substance changes). Therefore, we have to look for anything that would change...

July 2, 2018

All elements on the periodic table (except H and He) follow the octet rule that states that atoms want to have an octet (eight) electrons in their outermost shell. From the question we know that the element is nonmetallic which means its on the right side of the periodic table. It needs to gain two electrons to be happy and fill its octet, which means it

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