Fertilizers usually contain two elements from Goup 5a, which are........................and phosphurus
Nitrogen
100
The pattern of repeating properties of elements revealed in the periodic table is known as the………………………
periodic law
100
Out of Bromine, Flourine, Iodine and chlorine which halogen is most likely to react?
Flourine
100
A member of the boron family has three valence electrons, while a member of the nitrogen family has?
5
100
Group 7A of the periodic table contains the?
halogens
200
Boron, has ………………….valence electrons
3
200
Mendeleev’s periodic table was useful because it enabled scientists to predict properties of unknown……………………..
elements
200
Among the Alkali metals, the tendency to react with other substances depends on what?
The number of valence electrons, As you move down the group the elements become more reactive
200
The tendency of an element to react is closely related to?
The number of valence electrons
200
List the properties of metals.
Conductive, malleable and ductile
300
From left to right across a period in the periodc table, elements become less………………..and more………………….in their properities.
Metallic, nonmetallic
300
Which element is found in most of the compounds in your body except for water?
Carbon
300
Which element is the most reactive out of Group 7A……Flourine, Bromine, Iodine and chlorine?
Flourine
300
Compare the valence electrons of Group 2A elements and Group 6A elements?
6a has more valence electrons
300
At room temperature none of the metals in the periodic table can be?
gases
400
Elements can be classified as metals, nonmetals, and………………………..
metalloids
400
To keep from reacting some highly reactive elements are stored in?
Argon
400
Which is the most reactive element from Group 1A?
Francium
400
As you move from left to right across a period, the number of valence electrons?
increases
400
What kind of element is silicon? Is silicon a better conductor of electric current than sulfur?
metalloid, it is a better conductor than sulfur
500
The atomic mass unit is defined as one twelth the mass of a(an)………………..-12 atom.
Carbon
500
What gases emit colors when an electric current is applied?
Noble Gases, Argon and Krypton and Neon
500
Answer Yes or No for these 3 elements (Flourine, Chlorine, Iodine)
Are they all halogens?
Do they react easily with metals/
Are they similar to noble gases?
Are they all nonmetals?
Yes, Yes, No, Yes
500
Atoms of the most reactive elements tend to have how many valence electrons?