Answer:
1) d = 2.4 g/cm³
2) m = 25 g
3) v = 126.7 cm³
Explanation:
Given data:
Mass of material = 24 g
Volume of material = 10 cm³
Density of material = ?
Solution:
Formula:
d = m/v
by putting value,
d = 24 g / 10 cm³
d = 2.4 g/cm³
2) Given data:
Density of material = 5 g/cm³
Volume of material = 5 cm³
Mass of material = ?
Solution:
Formula:
d = m/v
5 g/cm³ = m / 5 cm³
m = 5 g/cm³×5 cm³
m = 25 g
3)Given data:
Density of material = 3 g/cm³
Mass of material = 380 g
Volume of material = ?
Solution:
Formula:
d = m/v
3 g/cm³ = 380 g / v
v = 380 g /3 g/cm³
v = 126.7 cm³
Answer:
Increasing atomic number - True
Explanation:
The modern table is based on Mendeleev’s table, except the modern table arranges the elements by increasing atomic number instead of atomic mass.
The Atomic number is the number of protons in an atom, and this number is unique for each element. For example, Hydrogen has an atomic number of 1, Calcium has an atomic number of 20.
In the modern periodic table the elements are further arranged into:
- rows, called periods, in order of increasing atomic number. Elements in the same periods have the same number of shells.
- vertical columns, called groups, where the elements have similar properties. Elements in the same group has the same number of valency (outermost number of electrons)
Natural abundance of oxygen I think
The percent composition of this compound :
Mg = 72.182%
N = 27.818%
<h3>Further explanation</h3>
Given
9.03 g Mg
3.48 g N
Required
The percent composition
Solution
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
Total mass of the compound :
= 9.03 g + 3.48 g
= 12.51 g
The percent composition :
Mg : 9.03/ 12.51 g x 100% = 72.182%
N : 3.48 / 12.51 g x 100% = 27.818%
Answer:
Element with 6s subshell
Explanation:
Reactivity of an element depends on the electronic configuration and position of element in the periodic table as reactivity increases as we go down the periodic table.
This is so because number of shell increases as move down the periodic table and the last electron is further away from the nucleus.
Element with 6s subshell is the largest among 3s and 4s subshell and has more number of shells so it will react more than 3s and 4s subshell.
Hence, the correct answer is "Element with 6s subshell".
