A physical change doesn't change what the substance is but for chemical change a new substance is formed and energy is either given off or absorbed.
Answer:
m = 19 grams
Explanation:
Given that,
No. of moles, n = 0.8
The molar mass of magnesium, M = 24.305 u
We need to find the mass of 0.80 moles of Mg. We know that given mass to the molar mass is equal to no of moles. Let the mass is m. So,

or
m = 19 grams
So, the mass of 0.8 moles of Mg is 19 grams.
Answer is: Te (tellurium).
During electron capture, iodine-123 f<span>orm the nearly-stable nuclide tellurium-123.
</span>In beta
plus decay (atomic number Z is decreased by one), a proton is converted to a neutron
and positron and an electron neutrino, so mass <span>number does not
change.
</span>Iodine-123 is a radioactive isotope of iodine used in nuclear medicine imaging.<span>
</span>
Answer: the answer is b: sp3d
Explanation: BrF3 has a Bent T shaped structure with Br as a central atom bonded with three F atoms (three bond pairs) and two lone pairs. Hence , the hybridization would be sp3d. Br atom has 7 electron in its outer most shell. After the bond formation of BrF3 molecule we have 3 bond pairs+ 2 lone pairs
This is a simple chemical change due to what it produces and how it is added together. Hope this helps.