When reaction with a chlorine atom, a sodium atom reacts by losing an electron to form the na+ ion, which is

A positive charge.

Positive charges happen when an atom loses an electron. In a normal state, atoms have equal amounts of protons (+) and electrons (-). So when they lose an electron they will have more protons (+) which will make it positive. Sodium has 11 protons + and 11 electrons -, take away an electron and it will go from a neutral charge to positive.

The residual value comes out to be 2.94 cm and height is 157.06 cm

Explanation:

The regression equation is calculated at the first step.

height = 105.08 plus 2.599 multiply foot length

At foot length = 20cm, height = 105.08 plus 2.599 multiply 20

= 157.06 cm

Residual = Actual minus predicted value = 160 minus 157.06

=2.94 cm

B) The residual standard deviation generally gives  a sense of the goodness of fit of goodness of regression equation on our data. The magnitude tells us that how much will be predicted values from model will vary from actual values. the linear model is justified.