Answer:
The periodic table is composed of seven horizontal rows or periods and is numbered between 1 and 7. There is a regular gradation in the properties of elements in the horizontal rows(periods) from left to right. The periodic table is composed of eight vertical columns or groups. They are numbered between 1 to 8.
Explanation:
Ca(OH)₂: strong base
pOH = a . M
a = valence ( amount of OH⁻)
M = concentration
Ca(OH)₂ ⇒ Ca²⁺ + 2OH⁻ (2 valence)
so:
pOH = 2 x 0.005
pOH = 0.01
pH = 14 - 0.01 = 13.99
Answer:
55.52°
Explanation:
Concept tested: Sine rule of triangles
We need to know the sine rule
- According to sine rule, if the three sides of a triangle are a, b and c and the corresponding angles, A, B and C
- Then,
In this case;
- If we take, a = 5.7 units and A = 70°, and
b= 5 units, B = x°
- Using the sine rule we can find the value of x
Therefore;
Then;
Therefore, X = 55.52°
Therefore, the value of x in the triangle is 55.52°
C. single replacement. A single replacement is represented by this formula : AB + C = AC + B