The total number of protons plus neutrons in an atom of ⁴⁵₂₀Ca is

A.) 20

B.) 25

C.) 45

D.) 65

Which of the following is a balanced chemical equation?

Which of the following shows the correct order of the body systems involved in this response? A. Integumentary, respiratory, digestive B. Circulatory, respiratory, nervous C. Integumentary, nervous, muscular D. Circulatory, digestive, nervous

You are in a car driving way from a stationary whistle. How does the sound you hear compare with that of the whistle itself? -You hear a higher pitch than the whistle makes. -Your motion is irrelevant to what you hear.

a neutral atom prossesses an atomic number of 15 and an atomic mass of 31. thress electrons are gained. what is the result of this conversation

Explain why it may make more sense to colonize on Venus, rather than Mars.

Two children playing on a frictionless garden gate invent a new game called "gate". The idea is that they will get on opposite sides of the gate and each push such that the gate does not move.

What is the frequency of 20 mm microwaves? A) 100 MHz B) 400 MHz C) 15 GHz D) 73 GHz E) 98 GHz

A measure of how much pulling, or tension, a material can withstand before breaking is - A. hardness. B. brittleness. C. tensile strength. D. malleability.

How work done against gravity can be expressed?

An electron is acted on by two electric forces, one of 2.7*10-14 N acting upward and a second of 5.8*10-14 N acting to the right. What is the magnitude of the electric field at the electron's location?