Answer:
a. atoms are the basic building blocks of matter. The atom is made of electrons and protons. It contains the chemical identity of an element.
b. Three types of particles that make up an atom are:
electrons - these are negatively charged particles and lightest constituents of an atom.
protons are positively charges and is 1873 times heavier than an electron.
Neutrons are neutral particles having mass equivalent to mass of proton.
Protons and neutrons exist in the center of an atom in nucleus and electrons revolve around the nucleus.
c. An atom is a neutral entity where as an ion is charged. An ion has excess of electrons or lacks electrons due to which it has negative or positive charge. An atom has an equal number of electrons and protons.
d. In a negative ion, the number electrons is greater than number of protons. The atom when gains electrons becomes negative ion.
e. John Dalton proposed Solid sphere model in which tiny invisible particles constitute matter. These invisible particles are atoms and these are indivisible.
<u>Correct Question:</u>
Calculate the distance (in km) charlie runs if he maintains an average speed of 8 km/hr for 1 hour
<u>Answer:</u>
The total distance covered by Charlie is 8 km in 1 hour.
<u>Explanation:</u>
The average velocity as given in the question is,
v = 8 km/hr
Total time taken,
As we know the formula to evaluate the total distance d when the average velocity and time is given;
Hence, the total distance covered by Charlie in 1 hour will be 8 km.
Answer:
(D) None
Explanation:
The force of gravity is the force pulling every element of matter together. The more the matter the higher the force of gravity.
Examples of this force at work are;
- The force that causes an apple to fall from the tree
- The force that causes a rock to roll downside a hill
- The force causing people to walk on the earth surface instead of floating
The force that facilitates a pen on your hand to write on a paper is friction force between the pen and the paper. Gravitational force acts downwards thus force applied on an object beside you is not the force of gravity.
