Answer:
1.6g/mL
Explanation:
Density equation is D=m/v
Density = g/mL
m=mass of sample in grams
v = volume of sample in mL
The volume of a square can be calculated by V=l*w*h.
In this case it is 5cm*5cm*5cm = 125cm^3
Since we know that 1cm^3 ~ 1mL we can convert the volume to mL as so:
125cm^3 (1mL/(1cm^3)) = 125mL
Then simply plug into the density equation:
D=200g/125mL = 1.6g/mL
Answer:
B) As you move across the row, the number of electrons increases and reactivity also increases.
Explanation:
The periodic table is arranged in a way that if you go across a period, the number of protons, neutrons, and electrons in an element increases. In terms of reactivity, the most reactive elements are the ones which have a high electronegativity. The electronegativity of the elements increases as you travel to the right and upwards on the periodic table.
Nitrogen. air consists 78% of nitrogen gas
