I think it's N and O because on the left 3 times 2 gives you O6 on the left but O3 on the right. Then on the right 1×2= N2 but on the right it's just N1
15.5% by mass is
equivalent 15.5 g urea in 100 g solution or 155 g urea in 1 kg solution. <span>
<span>we know that molality = moles solute / kg solvent
<span>moles solute = 155 g / 60 g/mol = 2.58 moles urea
</span></span></span>
Since there are 155 g
urea in 1000g solution, hence the solvent is 845 g or 0.845 kg
So:<span>
<span>molality = 2.58 / 0.845 = 3.06 m</span></span>
<span>Sodium
matches with malleable, soft and shiny
These are tyipical properties of alkalyne metals. You can cut sodium with a knife as it is very soft.
Bromine matches with highly reactive gas
Bromine is an halogen and indeed is very reactive
Silicon matches with has
properties of both metals and nonmetals
Silicon is a metaloid so it has some properties of metals and some of nonmetals.
Argon matches with non reactive gas.
Argon is a noble gas, and as such it is not reactive.
</span>
Pluto was ruled not a planet anymore because it is a "dwarf planet"
Apparently, the International Astronomical Union's (IAU) definition of a planet includes that a planet should be part of a body that would orbit the sun.
According to the IAU, there are three criteria's that contribute to a planet being called a planet.
1. It is within orbit around the Sun.
2. It has a sufficient mass to assume a nearly round shape
and 3. It has "cleared the neighborhood" around it's orbit.
Pluto only so happens to meet 2 of these requirements, not including the third option.