Answer:
alkali metals: 1 valence electron, very reactive metals
alkaline earth metals: 2 valence electrons, reactive metals
halogens: 7 valence electrons, very reactive nonmetals
noble gases: 8 valence electrons, very little reactivity
Explanation:
The groups increase by 1 valence electron as you move from left to right across the periodic table, skipping over the transition metals. The closer an element is to having a full octet of 8 valence electrons, the more reactive it will be. The alkali metals and halogens are both just 1 away from an octet -- alkali lose an electron, halogens gain one. This makes them very reactive.
Hello,
An answer is the group of reactive nonmetals and Noble gases.
I am not sure what the colored boxes mean, referring to my periodic table. However, the nonmetals are Hydrogen, Carbon, Nitrogen, etc., including the Noble gases.
Green and purple below, then hydrogen of course.
Where are the statements? Comment them and I'll give you the answer :)
Answer:
The mass of glycerol that the student should weigh out depends on the volume that is needed. For example, the density of glycerol is 1.26 g/mL. Then, if 500 mL of glycerol is needed, 630 g should be weighed.
Explanation:
Density is the amount of mass per unit of volume. Density relates how many grams 1 milliliter of a substance weighs. Thus, if the density of glycerol is 1.26 g/mL means that 1.26 grams of glycerol occupy 1 mL of volume, or, in other words, 1 mL of glycerol weighs 1.26 grams.
Therefore, if 500 mL of glycerol is required to use for an experiment, 630 grams need to be weighed:
1 mL glycerol________ 1.26 g
500 mL glycerol______ x= 500mL * 1.26 g / 1 mL = 630 g