what is the difference between char and int used in scanf function in a loop? [duplicate]

Question

when I write a for loop to scanf some int value, the output is correct. however, I try to this loop to scanf some char value, it seems something wrong.(I was wondering the space or '\t' as a char to be scanned)

//when the input are
2
1 2
3 4
//
#include<stdio.h>
int main(void){
    int n;
    scanf("%d", &n);
    int x;
    int y;
    for(int i = 0; i< n; i++){
        scanf("%d %d", &x, &y);
    }
    return 0;
}
//when I enter
2
a b
the program is finished and i cannot enter more char.
//
#include<stdio.h>
int main(void){
    int n;
    scanf("%d", &n);
    char x;
    char y;
    for(int i = 0; i< n; i++){
        scanf("%c %c", &x, &y);
    }
    return 0;
}

Answer 1

Remember, the space (' ') is also a char, so the scanf is reading the space instead of the second letter.