What's the big M? Molecular weight or mol?
Answer: 128 g/mol
Explanation:
Graham's law states that the rate of effusion of a gas is inversely proportional to the square root of the molar mass of its particles.
Mathematically, that is:

Since, you know the ratio of two rates and the molar mass of one gas, you can calculate the molar mass of the other gas.
The molar mass of the oxygen molecule, O₂ = 2×16.0g/mol = 32.0 g/mol.
In the coming equations, I will use 32 g/mol for simplicity of writing.

So, the molecular mass of the unnknown gas is 128 g/mol.
Basically, an element<span> is made of only one kind of atom, while a </span>compound<span> contains the atoms of two or more </span>elements<span>.
Just to give you a good exaple:
Gold is made of only one kind of atom, so it's considered an </span>element<span>, but water is a mix of hydrogen and oxygen, so it's a </span>compound<span>.</span>
Answer:
Hard parts of the organism must dissolve
Explanation:
I just took the quiz/test and got it right
Ionic Bonding:
This type of bonding occurs when atoms want to fulfil their valence shells by taking/giving electrons to other atoms. This, leads to completed valence shells in most cases and ionisation of both elements. The opposite charges cause the elements to stick together because opposites attract.
Covalent Bonding:
This type of bonding occurs when electrons are shared between atoms to each fill up their own valence shells by sharing. The balance between the attraction forces and repulsion forces between the shared electrons is called covalent bonding.
Hope I helped :)