Urgent Chemistry Help Needed!!!!

I didn't do the reading this week and there's no way i'm catching up. I'd really like some help on these questions, it's a major part of our grade. I hear they're not too difficult, but I can't find much of anything on google.


2.1.1

How is the electron configuration of an anion different from that of the corresponding neutral atom?

How is the electron configuration of a cation different?



2.1.2

Which of the transition elements in the first transition series have anomalous electron configurations?

Explain the relationship between the properties of an element and the number of valence electrons.



2.1.3

What were the contributions of Dobereiner and Newlands to the organization of the elements according to their properties?
Explain the contributions of Meyer and Moseley to the periodic table.



2.1.4

What observations led to the periodic law? What theory explains the underlying reasons for the periodic law?


Who is credited with arranging the periodic table?How were elements arranged in this table?



-Just so you know, you don't need to know all of them to post. Just please be accurate and answer the ones you can. You're allowed to get them from any source, but please cite them so you're not plagiarizing.

 

"Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869, who intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior."

http://en.wikipedia.org/wiki/Periodic_table
------

What grade is this?
Also, are you good at math by any chance? :/ (need to do my grade 11 U math today and I don't understand it >.<)

 

1) Please state which question you're answering, i'm guessing your attempting to answer the very last one.

2) Anything but geometry, but PM me so you don't hijack.

 

How is the electron configuration of an anion different from that of the corresponding neutral atom?

An anion is a negatively charged ion, this would mean that the anion has one or more extra electron (Negative charge) than that of the neutral atom. Also, anions have the end -ide on the ion.

How is the electron configuration of a cation different?

A cation is a positiviely charged atom, this would mean that the cation has one LESS electron making it have a positive charge.

Example of anion:
Neutral chlorine atom = 17 Electrons, 17 Protons
Chloride ion = 18 electrons, 17 protons

Example of cation:
Neutral sodium atom = 11 electrons, 11 protons
Sodium ion = 10 electrons, 11 protons

Which of the transition elements in the first transition series have anomalous electron configurations?

I think the metals in the "D" block in the periodic table. The ones in the first transition series that have this configuration are Chromium and Copper

Explain the relationship between the properties of an element and the number of valence electrons.

Atoms in the same group have similar chemical properties, this is one of the most important rules in chemistry. Each group 1 element has a valence electron of s1, each group 2 element has a valence electron configuration of s2.

What observations led to the periodic law? What theory explains the underlying reasons for the periodic law?

Moseley's observations led to the periodic law. He discovered the atoms of each element contain a unique number of protons in their nuclei; Atomic number = Number of protons. He arranged the atoms by increasing atomic number, this is the periodic law. (Not sure what theory explains it)

Who is credited with arranging the periodic table?How were elements arranged in this table?

Mandeleev is credited with arranging the periodic table, he arranged them in order of increasing atomic mass, leaving space for new elements that had not been found.

What were the contributions of Dobereiner and Newlands to the organization of the elements according to their properties?

I'm not sure about Dobereiner, but I know about Newlands. Newlands proposed an organizational scheme for the elements by his "law of octaves". This law stated that the properties of elements repeated for every eighth element; this law was hampered as it did not work for all elements. Though he was proven wrong, he was still correct in a way; the properties of elements do repeat in a periodic way.

Explain the contributions of Meyer and Moseley to the periodic table.

As stated before, Moseley discovered the atoms of each element contain a unique number of protons in their nuclei; Atomic number = Number of protons. He also came up with the periodic law.

Meyer demonstrated a connection between atomic mass and elemental properties and arranged the elements in order of increasing atomic mass.


Here is a little review on the scientists who contributed to the periodic table I have in my old chemistry book:

 

If you still need help with this in 3-4 hours, let me know. I'm heading off to biology lab, but I can answer them all when I get back.

 

Everything was answered.

Closed.