in a laboratory activity, the density of a sample of vanadium is determined to be 6.9 g/cm3 at room temperature. what is the percent error for the determined value?

a)
0.15%
b)
0.87%
c)
13%
d)
15%

When the measured density of a sample of vanadium at room temperature is 6.9 g/cm³, we can conclude that, in relation to its true value (6.1 g/cm³) there is a percent error in the measurement of 13 % (Option C).

In a laboratory activity, the density of a sample of vanadium is determined to be 6.9 g/cm³ at room temperature. This is the experimental value.

According to the literature, the density of vanadium at room temperature is 6.1 g/cm³. This is the true value.

We can find the percent error of the measurement using the following expression.

When the measured density of a sample of vanadium at room temperature is 6.9 g/cm³, we can conclude that, in relation to its true value (6.1 g/cm³) there is a percent error in the measurement of 13 % (Option C).

You can learn more about percent error here:

The name of the compound is Copper(II) oxide and it is also known as cupric oxide.

The name of the compound contains the name of both elements/atoms in the compound. Cu stands for copper while O stands for oxygen.

Any compound containing the oxygen is known as oxide. So copper containing the one oxygen will be copper(II) oxide. The (II) shows the oxidation state of copper. And any copper compound which has oxidation state of 2 can be known as cupric.

CuO is the ionic compound. And its valency shows the bond type.

First separate the atoms in the compound.

Then identify their valencies. The valency of Cu is 2 which valency of oxygen is 6.

If valency is 4, it means half of the shell is full and it is difficult for the atom to lose or gain electrons. In that case it will make covelent bond.

But if valency is higher or lower than 4, it is feasible to make ionic bond.

Hence CuO will make a ionic bond.