What did Thomson’s discovery of electron properties do to the atomic theory?
Thomson determined mass was smaller than the mass of atom.
100
What are some properties of alkali metals?
The properties of alkali metals are that they are silvery can be cut with a knife, and they are the most reactive metals. These have one valence electron.
100
What is the trend for atomic radii?
The trend for atomic radii is that it increases from right to left because the positive charge is higher on the right which is pulling the electrons closer. It also increases going down a group because of adding energy levels.
100
How did Mendeleev organize his periodic table?
He organized the 1st periodic table and left blanks for the undiscovered elements.
100
What was Dalton's atomic theory?
He hypothesized that the atoms of an element had the same number of mass, size, and etc.
200
What was Thomson’s atomic model called?
His model was called “plum pudding."
200
What are some properties of alkaline earth metals?
The properties of alkaline earth metals are that they are harder, denser, stronger, and slightly less reactive than group These have two valence electrons.
200
What is the trend for ionic radii?
The trend for ionic trend is that cation and anion increases from right to left across the period. It’s radii also increases down a group.
200
How did Mosely organize the periodic table?
He organized the elements by their atomic number.
200
Was Dalton's atomic theory completely right or not? If not, then explain.
Dalton's atomic theory wasn't completely right because the atoms of an element don't have the same number of mass because the isotopes of an element can vary.
300
What makes each element or group different from each other?
They all have a different atomic number and properties.
300
What are some properties of halogens?
The properties of halogens are that they are the most reactive nonmetals. These have 7 valence electrons.
300
What is the trend for electrogravity?
The trend for electrogravity is that it decreases as you move it to the left of the period. It decreases or stays the same moving down a group.
300
What did scientist Mosely do to contribute to the development of the periodic table?
In 1911, Mosely found on how to arrange the periodic table by the elements’ atomic number.
300
What can or/and cannot occur to atoms?
Atoms can’t be divided, created, destroyed, or become smaller, but they can combine in ratios that form compounds. They can be combined, separated, or rearranged if a chemical reaction occurs.
400
What did Rutherford's experiments find over the nucleus?
From his experiments he found that the nucleus of the atom is very dense and has a positive charge.
400
What are some properties of noble gases?
The properties of noble gases are that they are nonreactive. These have 8 valence electrons.
400
What is a trend for ionization energy?
The trend for ionization energy is that it decreases when you move it to the left because those elements readily give up an electron.
400
What kind of connection did Mendeleev discover with the atoms?
He discovered a connection with the atomic mass and elemental properties.
400
What else is incorrect about Dalton's atomic theory?
What Dalton got wrong about atoms is that they can’t be divisible and atoms of the same element do not have the same mass.
500
What are some differences of Bohr’s and Rutherford’s nuclear atom?
Rutherford used a gold foil experiment to discover existence of nucleus, dense region in center of atom which is positively charged and contains virtually all of its mass.
Bohr was a danish physicist who made foundational contributions to understanding atomic structure and quantum theory
500
What are some properties of transition metals?
The properties of transition metals are that they are good conductors of heat/electricity, have high luster, and they are not as reactive as group 1 & 2 elements. These vary the # of valence electrons they have but the common one is 2 valence electrons.
500
What is another trend for ionization energy?
It also decreases as you move it down a group due to the electrons being further away from nucleus and shielded by inside electrons.
500
What did Mendeleev find in 1869?
In 1869, Mendeleev found out how to arrange the elements by their atomic mass and similar chemical properties.
500
What are cathode-ray particles and what do they determine?
Cathode-ray particles later named electrons determined that charged particle mass was less than that of a smallest element hydrogen.