Science Chapter 24 Lesson 1
Mendeleev placed elements in rows of _________.
Increasing atomic mass
What is the periodic table?
a chart of elements arranged in rows and columns according to their physical and chemical properties
What is a group?
a column on the periodic table
What is a period?
a row on the periodic table
In the mid 1800s, Russian chemist and teacher named Dmitri Mendeleev created what?
a table to help classify the elements by their properties
When reading from left to right on the periodic table, what two things increase by one?
atomic number and chemical and physical properties
How can you identify many of the properties of an element?
from its placement on the periodic table
What can the periodic table be used to determine?
how all elements are related to each other
After arranging the known elements in a periodic table, Mendeleev noticed what? What did he predict from this?
large gaps between some elements; he predicted new elements would be found to fit into those spaces
What is in between and has properties of both nonmetals and metals?
metalloids
Most of the elements on the periodic table are metals, nonmetals, or metalloids?
metals
What is the word periodic used to describe?
repeating patterns
Elements that are near each other on the periodic table share what?
similar properties
The number of protons in the nucleus of an atom is called what?
the atomic number
In the early 1900s, Henry Moseley found that the problem in Mendeleev's periodic table could be solved how?
the elements had to be arranged in rows by atomic number
What does the element's key show?
the elements name atomic number chemical symbol state of matter atomic mass
Mendeleev noticed patterns in what?
the melting points of elements (the temperature at which a solid changes to a liquid)
What side of the periodic table are most nonmetals on?
the right side
What did Mendeleev predict about the pattern of elements in the periodic table?
there were large gaps between some elements and the properties of these elements would be similar to the known elements in the same columns
What do elements of the same group have in common?
they all have similar properties, which means they react with each other in similar ways
What do nonmetals not do that metals do?
they are not good conductors of electricity and thermal energy
Give two chareristics of metals.
they are shiny and good conductors of thermal energy and electricity
What do scientists use the periodic table for?
to predict the new properties for elements they create
