<span>increase while moving left to right within a period and increase while moving upward within a group. </span>
Answer:
c
Explanation:
chemicals can be found in every part of our lives
Oxidation is the half reaction that can occur at the anode in a voltaic cell.
Explanation:
In electrodes which is metal strip in voltaic cell the reactions occurs. The two electrodes placed one in each half-cell. The reduction reaction occurs at cathode and oxidation occurs at anode.
A half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction. Half-reactions are often used as a method of balancing redox reactions.
In an oxidation half reaction, an atom loses electron(s). When an element is oxidized it loses a specific number of electrons.
The given question is incomplete. The complete question is :
Which of the following Group 17 elements is the least reactive
a) Flourine
b) Chlorine
c) Astatine
d) Iodine
Answer: c) Astatine
Explanation:
Halogen is the name given to Group 17 family with general electronic configuration of 
which have 7 valence electrons and thus easily gain one electron to attain stable configuration.
As we move down the group from flourine to chlorine to bromine to iodine to astatine , the valence shell moves farther from nucleus and thus tendency to accept the electron decreases and thus reactivity also decreases.
Thus Astatine is the least reactive of all.
Answer:
1.0 × 10⁸ ruthenium atoms
Explanation:
Step 1: Calculate the diameter (d) of an atom of ruthenium
The diameter of an atom is twice its radius.
d = 2 × r = 2 x 178 pm = 356 pm
Step 2: Convert "d" to meters
We will use the conversion factor 1 m = 10¹² pm.
356 pm × 1 m/10¹² pm = 3.56 × 10⁻¹⁰ m
Step 3: Convert the distance of the tip of a finger (D) to meters
We will use the conversion factor 1 m = 10² cm.
3.6 cm × 1 m/10² cm = 0.036 m
Step 4: Calculate the number of atoms of ruthenium required
We will use the following expression.
D/d = 0.036 m/3.56 × 10⁻¹⁰ m = 1.0 × 10⁸
