2- A gas has a volume of 500 mL at a temperature of -73.0 °C. What volume will the gas
occupy at 27.0°C?

750ml

Explanation:

Using charle's law

V1/T1=V2/T2

V1= 500ml

T1= -73⁰C

V2= ?

T2=27⁰C

We can see that the temperature is in Celsius

Now,we will convert to Kelvin

Kelvin= 273+ Celsius

So convert the Celsius value to Kelvin

For T1= 273+(-73)

T1= 273-73

T1= 200K

For T2= 273+27

T2= 300K

V1/T1=V2/T2

500/200=V2/300

Cross multiply

200×V2=500×300

200V2= 150000

V2= 150000/200

V2= 750ml

So,

750ml of gas will occupy at 27⁰C

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms