Tính thể tích khí H2 điều kiện tiêu chuẩn thu được khi nào 11,2gam Fe tác dụng với a) dung dịch H2SO4 loãng dư
b) 150ml dung dịch H2SO4 1M

u

r

m

o

m

Explanation:

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.