Answer:
Elements having same valence electrons are placed in <u>same group.</u>
Explanation:
First, let's start with some basic concepts of modern periodic table:
1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers
The Modern periodic table is divided into Periods and groups .
Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.
Same period have same number of atomic orbital(Shell)
Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.
So, elements showing same valency are placed in same group.
All alkali are place in group 1 and have 1 valance electron in the outermost shell
Answer:
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution.
Explanation:
<em>Which of the statements correctly describe the properties of a buffer?</em>
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution. TRUE. The conjugate base neutralizes the excess of hydrogen protons.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base. TRUE.
c. An acidic buffer solution is a mixture of a weak base and its conjugate acid. FALSE. This is a basic buffer solution.
d. The weak acid of an acidic buffer will accept hydrogen protons when a strong base is added to the solution. FALSE. The weak acid will react with the hydroxyl ions from the added base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution. TRUE. These hydrogen protons will form water.
f. The conjugate base of an acidic buffer will donate hydrogen protons when a strong acid is added to the solution. FALSE. It will accept hydrogen protons.
d answer is correct that help
Percent error (%)= 
Accepted value is true value.
Measured values is calculated value.
In the question given Accepted value (true value) = 63.2 cm
Given Measured(calculated values) = 63.1 cm , 63.0 cm , 63.7 cm
1) Percent error (%) for first measurement.
Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.1 cm
Percent error (%)=
Percent error = 0.158 %
2) Percent error (%) for second measurement.
Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.0 cm
Percent error (%)=
Percent error = 0.316 %
3) Percent error (%) for third measurement.
Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.7 cm
Percent error (%)=
Percent error = 0.791 %
Percent error for each measurement is :
63.1 cm = 0.158%
63.0 cm = 0.316%
63.7 cm = 0.791%
