Ch. 5 Flashcards Preview

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Flashcards in Ch. 5 Deck (41):
0

The first elements to be identified were mainly what?

Metals

1

What were elements organization based on?

On their properties

2

What was Mendeleev's strategy for classifying elements modeled on?

Card game

3

What did Mendeleev know about each element?

The name, relative mass, and properties

4

How did Mendeleev arrange the elements into rows?

By their increasing masses

5

A periodic table is an arrangement of ________ in columns, based on a set of properties that repeat from row to row.

Elements

6

Why did Mendeleev leave some locations on his periodic table blank?

He left them for elements that had not been discovered

7

Was Mendeleev the first person to arrange the elements in a periodic table?

No

8

How can you tell if a scientific model is correct?

By wether it can be used to make accurate predictions

9

What did Mendeleev use to locate undiscovered elements?

Properties of elements

10

What did the close match between Mendeleev's predictions and the actual properties of new elements show?

The usefulness of his periodic table

11

How are elements arranged in the modern periodic table?

By the increasing number of protons

12

Why does the number of elements per period vary?

The number of available orbitals increases from energy level to energy level

13

What value depends on the distribution of an elements isotopes in nature?

Atomic mass

14

Most elements exist as what?

A mixture with two or more isotopes

15

Is the mass of chlorine-37 greater or smaller than the mass of the atom chlorine-35?

greater

16

Name the three categories into which elements are classified into based on their general properties.

Metals
Nonmetals
Metalloids

17

Do all metals react to oxygen in the same way?

No

18

Across a period from left to right, the element becomes (more, less) metallic and (more, less) nonmetallic in their properties.

Less,
More

19

Elements within a group have the (same, different) number of valence electrons.

Same

20

The reactivity of alkali metals (increases, decreases) from the top of Group 1A to the bottom.

Increases

21

Why is sodium stored under oil?

Because it reacts with water vapor in the air

22

Differences in reactivity amount on the alkaline earth metals are shown by the way they react with what?

Water

23

What does magnesium help/used for?

Helps plants produce sugar,
Is used to make lightweight bicycle frames

24

What does calcium help/used for?

Helps build strong teeth,
Is the main ingredient in limestone

25

Is aluminum more reactive than sodium and magnesium?

No

26

What is the most abundant metal in Earth's crust?

Aluminum

27

Aluminum is often found combined with oxygen and what?

Bauxite

28

Except for water, what compound is most contained in your body?

Carbon

29

What is the most abundant element in Earth's crust?

Oxygen

30

Halogens have similar ________ properties but different __________ properties.

Chemical,
Physical

31

What are three characteristics of the noble gasses?

Colorless,
Odorless,
Extremely unreactive

32

How can an element that does not react easily with other elements be useful?

It can be used to prevent reactions with highly reactive elements

33

Define the following:
An arrangement of elements in columns based on a set of properties that repeat from row to row

Periodic table

34

Define the following:
A pattern of repeating properties that occurs when atomic numbers are used to arrange elements into groups

Periodic law

35

Define the following:
One-twelfth the mass of a carbon-12 atom

Atomic mass unit

36

Define the following:
Elements that are good conductors of heat and electric current

Metals

37

Define the following:
Elements that form a bridge between the elements on the left and right sides of the periodic table

Transition metals

38

Define the following:
Elements that are poor conductors of heat and electric current

Nonmetals

39

Define the following:
Elements with properties that fall between those of metals and nonmetals

Metalloids

40

Define the following:
An electron that is in the highest occupied energy level of an atom

Valence electron