Error: Unsupported argument

on test.tf line 14, in resource “aws_instance” “test”:
14: root_block_device = {

An argument named “root_block_device” is not expected here. Did you mean to
define a block of type “root_block_device”?

resource “aws_instance” “test” {
ami = “JMdkQ5aOmNIzzceMwHhNZ0SX15b+2uslQX3cZ9qt”
instance_type = “t2.micro”
key_name = “sar-test”
availability_zone = “ap-south-1c”
security_groups = “{aws_security_group.allow_SSH.id}" subnet_id = "subnet-7738e40c" root_block_device = { volume_size = 10, delete_on_termination = true, encrypted = true, device_name = "/dev/sda1" } #"{root_block_device.HD1.id}”
}

resource “aws_security_group” “allow_SSH” {
ingress {
from_port = 22
to_port = 22
protocol = “-1”
cidr_blocks = [“0.0.0.0/0”]
}

ingress {
from_port = 80
to_port = 80
protocol = “-1”
cidr_blocks = [“0.0.0.0/0”]
}
}

#resource “aws_root_block_device” “HD1” {

volume_size = “10”

delete_on_termination = “true”

encrypted = “true”

device_name = “/dev/sda1”

#}

Im trying to provision a AWS Ec2 instance this is the basic code im gonna use, there is a error.
Kindly Someone help…

Kindly Go through the complete code and help me with the corrections.

Thanks in Advance