Answer: -
Organic compounds consisting of only carbon atoms and hydrogen atoms are known as hydrocarbons.
Hydrocarbons are used by us for mainly as a source of energy. Hydrocarbons make up gasoline which is used as fuel in automobiles.
Hydrocarbons depending on the type of unsaturation can be of three types - alkanes, alkenes and alkynes.
Answer: The momentum of the child and milk together is 58.125 kg.m/s
Explanation:
Momentum is defined as the product of object's mass and velocity.
Mathematically,

where, p = momentum
m = mass of the object
v = velocity of the object
In the given question, we are given that a child of mass 21.0 kg is carrying a gallon of milk having mass 2.25 kg and running with a velocity of 2.5 m/s. Hence, the momentum by both milk and child will be:
....(1)
Given:

Putting values in equation 1, we get:

Hence, the momentum of the child and milk together is 58.125 kg.m/s
Answer:
A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom
Explanation:
so In simple terms an atom contains Protons and Electrons and can be found in an Element, but an element comprises of atoms which come together to form up that particular Element
1: the symbol of the metal should be written first.
2: the valency of the elements or radicals should be interchanged.
Answer:
No
Explanation:
The mass fraction is defined as:

where:
- wi: mass fraction of the substance i
- mi: mass of the substance i
- mt: total mass of the system
<u><em>The mass fraction of two substances (A and B), will be the same, ONLY if the mass of the substance A (mA) is the same as the mass of the substance B (mB).</em></u>
An equimolar mixutre of O2 and N2 has the same amount of moles of oxygen and nitrogen, just to give an example let's say that the system has 1 mole of O2 and 1 mole of N2. Then using the molecuar weigth of each of them we can calculate the mass:
mA= 1 mole of O2 * 16 g/1mol = 16 g
mB=1 mole of N2 *28 g/1mol=28 g
As mA≠mB then the mass fractions are not equal, so the answear is NO.