Answer:
Group 1 (or IA)
Explanation:
If element X is a halogen, then it belongs to the group 17 (or VIIA, under a different notation).
For each extra unit of atomic number, the group number increases by 1. That means that the X+1 element would belong to the group 18 (or VIIIA). <em>The X+2 element would thus belong in the group 1 </em>(or IA) one period higher (higher as in numeric value, not as in position in the periodic table).
Answer:
where are the statements??
Explanation:
Answer:
1.07×10²¹ molecules are needed to sound the alarm
Explanation:
Let's convert the mass of CO to moles, to determine the amount of molecules.
0.05 g . 1 mol / 28 g = 1.78×10⁻³ moles
Now we can determine the number of molecules with the NA
1 mol has 6.02×10²³ molecules
1.78×10⁻³ moles may have (1.78×10⁻³ . 6.02×10²³) / 1 = 1.07×10²¹ molecules
Answer:
2= its color
Explanation:
Transition elements are present in the middle of periodic table. These are d-block elements.
These are 38 elements.
All transition elements have partially filled d orbitals.
They showed color in compound because of d-d transition.
During the d-d transition electron absorbed the energy and emit the reminder energy. The emission is usually in the form of color light.
The color of ion is complementary to the absorbed color.
The transition elements are used as a catalyst in industries such as polymer, petroleum industries.
They are ductile, conduct heat and electricity.
Physical changes occur when the properties of a substance are retained and/or the materials can be recovered after the change. Chemical changes involve the formation of a new substance. Formation of a gas, solid, light, or heat are possible evidence of chemical change.
