Answer : The half life of 28-Mg in hours is, 6.94
Explanation :
First we have to calculate the rate constant.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time passed by the sample = 48.0 hr
a = initial amount of the reactant disintegrate = 53500
a - x = amount left after decay process disintegrate = 53500 - 10980 = 42520
Now put all the given values in above equation, we get


Now we have to calculate the half-life.



Therefore, the half life of 28-Mg in hours is, 6.94
Answer:
A. tungsten
Explanation:
Tungsten is a material which high melting point ie. does not melt easily incase of high temperature
Answer:
Sound waves need to travel through a medium such as solids, liquids and gases. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly. Liquids are not packed as tightly.Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. Temperature also affects the speed of sound.Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. A vibrating string can create longitudinal waves as depicted in the animation below.
Explanation:
Answer:Light bounces off of the mirror and then appears to come from behind the mirror.
Explanation:Plane mirrors form images that are virtual, upright and the same size and shape as the object it is reflecting.
When rays of light from the object hits a plane mirror they bounces off the mirror,that is they undergo reflection, and appear to originate from behind the mirror, resulting to the formation of a virtual image.
The image formed appears to be behind the plane in which the mirror lies. A virtual image is an image that is formed at a location from which the rays of light appear to come from. The image can not be formed on a screen..