The similarities of physical and chemical changes is that both of those changes change the way the object looks by it's physical appearance. Also they use a type of element to change that object.
False... The number of electrons in the outer shell of the atom of the element determines it's reactivity. <span />
Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
We measure temperature in degrees of Fahrenheit
V2 = 250 ml
Explanation:
Given:
P1 = 0.99 atm. V1 = 240 ml
P2 = 0.951 atm. V2 = ?
We can use Boyle's law to solve for V2
P1V1 = P2V2
V2 = (P1/P2)V1
= (0.99 atm/0.951 atm)(240 ml)
= 250. ml
