what does an element contain?

what is group 1 of the periodic table?

what are the properties of an alkali metal?

how many elements exist?

state symbols

what do halogens consist of?

what is an important thing to note?

Who arranged the modern periodic table?

what happens to elements when they are heated?

what is inside an atom?

how is the modern periodic table arranged?

how are electrons arranged?

what are the alkali metals?

what are the halogens?

What are examples of halogens?

what do group 7 elements need?

what are ionic compounds?

why are they ionic compounds?

what are properties of ionic compounds?

when do positive and negative ions form?

some chemical elements