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Flashcards in the periodic table (C3) Deck (15):
1

What are the 2 scientists which developed the early periodic table?

Newland and Medeleev

2

What did Newland add to the early periodic table?

- sometimes2 elements in the same box
-arrangement by atomic mass (weight)
-based from Daltons law of octaves

3

What is Daltons law of octaves?

every 8th element has similar properties

4

What did Medeleev add to the early periodic table?

-arrangement by atomic mass (weight)
-grouped by similar properties
-left gaps for elements not yet discovered
-arranged regularly/periodically (groups and columns)

5

What are the features of the modern periodic table?

-arranged in metals and non metals
-arranged by number of protons
-arranged in groups
-arranged in periods
-all elements now in appropriate groups

6

What does the group tell us about an element in the modern periodic table?

the number of electrons an element has in its outer shell

7

What does the period tell us about and element in the modern periodic table?

the number on shells an element has

8

what was discovered in the early 20th century?

protons, neutrons, and electrons

9

what was discovered in Mendeleev's lifetime which supported his periodic table?

3 elements that fitted in some of the gaps he had left

10

what trends do we find within the periodic table?

reactivity

11

how can trends in reactivity be explained?

the number of electrons in higher energy outer shell (whether its easier to gain or loose electrons)

12

what reactivity trend is present in group 1 (alkali metals)?

the lower in the group the higher the reactivity

13

why do we see the trend in reactivity we see present in group 1 (alkali metals)?

the elements at the top of the group are less reactive because the outer shell of electrons is the nucleus which has an attraction

14

what reactivity trend is present in group 7 (the halogens)?

the higher up the group the more reactive

15

why do we see the trend in reactivity we see present in group 7 (the halogens)?

the elements at the top of the group have outer shells which are closer to the positively charged nucleus