Answer:
A)The spring scale has a high level of precision and a low level of accuracy.
Explanation:
Hope it works for u guys
Let us assume that there is a 100g sample of Opal. The masses of each element will be:
29.2g Si
33.3g O
37.5g H2O
Now we divide each constituent's mass by its Mr to get the moles present
Si: (29.2 / 28) = 1.04
O: (33.3 / 16) = 2.08
H2O: (37.5 / 18) = 2.08
Now we divide by the smallest number and obtain:
Si: 1
O: 2
H2O: 2
Thus, the empirical formula of Opal is:
SiO2 . 2H2O
The correct option is COVALENT BONDS.
A Lewis acid is defined as a substance which accept a pair of electron while a Lewis base refers to a substance that donate an unshared pair of electrons to another chemical specie with which it shared the donated pair of electrons.
Lewis acid and Lewis base react together to form salt and water. This type of reaction is called neutralization reaction. The neutralization reaction of Lewis acid and Lewis base involves electron pairs transfer, thus, there is an increase in the number of covalent bonds during this reaction.
Answer:
At -13
, the gas would occupy 1.30L at 210.0 kPa.
Explanation:
Let's assume the gas behaves ideally.
As amount of gas remains constant in both state therefore in accordance with combined gas law for an ideal gas-

where
and
are initial and final pressure respectively.
and
are initial and final volume respectively.
and
are initial and final temperature in kelvin scale respectively.
Here
,
,
,
and
Hence 



So at -13
, the gas would occupy 1.30L at 210.0 kPa.