Answer: 
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
General representation of an element is given as:
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
The balanced nuclear equation when the isotope Strontium-90 decays by Q- decay is :

Answer:
Plants use photosynthesis to make glucose. Glucose is also know as sugar. You can tell it is present if the plant receives sunlight as well as water.
Explanation:
MARK BRAINLIEST
Density/Earth’s gravitational pull.
Explanation:
Atomic Number = Number of protons
Mass Number = Number of protons + Number of neutrons
Isotopes are simply atoms of an element with the same number of protons and different number of neutrons.
First Isotope -- 238U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 238 - 92 = 146
Second Isotope -- 235U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 235 - 92 = 143
A specific combination of bonded atoms which always react in the same way, regardless of the particular carbon skeleton is known as the functional group. These are specific groups of atoms or bonds within organic molecules that accounts for the characteristic chemical reactions of those molecules. Examples of functional groups are the Carbonyl group, alkyl Halides, aldehydes and ketones among others.